added 1918A, 1918B and 1927(A-D)

Codes/1918 A - Brick Wall/1918A.cpp

@@ -0,0 +1,72 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define FAST_IO             (ios_base:: sync_with_stdio(false),cin.tie(NULL));
+
+#define int                 long long
+#define ll                  long long
+#define ull                 unsigned long long
+#define endl                '\n'
+#define ff                  first
+#define ss                  second
+#define pb                  push_back
+#define all(x)              x.begin(), x.end()
+#define sz(x)               (int)(x).size()
+
+#define yes                 cout<<"YES"<<endl
+#define no                  cout<<"NO"<<endl
+#define neg1                cout<<-1<<endl
+
+#define PI                  3.141592653589793238
+#define MIN                 INT_MIN
+#define MAX                 INT_MAX
+#define INF                 LONG_LONG_MAX
+#define MOD                 1000000007
+#define LLM                 1000000000000000007
+
+ll factorial(ll n)              { if(n==0) return 1; ll res = 1; for (ll i = 2; i <= n; i++) res = res * i; return res; }
+ll nPr(ll n, ll r)              { return factorial(n) / factorial(n - r); }
+ll nCr(ll n, ll r)              { return factorial(n) / (factorial(r) * factorial(n - r));}
+ll gcd(ll a, ll b)              { if (b == 0) return a; return gcd(b, a % b); }
+ll lcm(ll a, ll b)              { return (a * b) / gcd(a, b);}
+ull mypow(ull a, ull b)         { ull ans = 1; a%=MOD; while(b){ if (b&1) ans = (ans*a) % MOD; a = (a*a) % MOD; b >>= 1; } return ans; }
+bool isPrime(ll n)              { if(n <= 1) return false; for(ll i = 2; i*i <= n; i++) if(n % i == 0) return false; return true; }
+
+#ifndef ONLINE_JUDGE
+#define dbg(x) cerr << #x <<" "; _print(x); cerr << endl;
+#define dbgin(x) cerr << #x <<" "; _print(x); cerr << ";"<<endl;
+#else
+#define dbg(x)
+#define dbgin(x)
+#endif
+
+void _print(int t) {cerr << t;}void _print(string t) {cerr << t;}void _print(char t) {cerr << t;}
+void _print(long double t) {cerr << t;}void _print(double t) {cerr << t;}void _print(unsigned ll t) {cerr << t;}
+template <class T, class V> void _print(pair <T, V> p);
+template <class T> void _print(vector <T> v);template <class T> void _print(set <T> v);
+template <class T, class V> void _print(map <T, V> v);template <class T> void _print(multiset <T> v);
+template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.first); cerr << ","; _print(p.second); cerr << "}";}
+template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(unordered_set <T> v) {cerr<<"[ "; for(T i : v) {_print(i); cerr<<" ";} cerr<<"]";}
+template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T, class V> void _print(multimap <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";} 
+template <class T, class V> void _print(unordered_map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void solve()
+{
+    int n,m;
+    cin>>n>>m;
+    cout<<n*(m/2)<<endl;
+}
+
+int32_t main()
+{
+    FAST_IO;
+    int TC = 1;
+    cin >> TC;
+    while (TC--) 
+        solve();
+}

Codes/1918 B - Minimize Inversions/1918B.cpp

@@ -0,0 +1,87 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define FAST_IO             (ios_base:: sync_with_stdio(false),cin.tie(NULL));
+
+#define int                 long long
+#define ll                  long long
+#define ull                 unsigned long long
+#define endl                '\n'
+#define ff                  first
+#define ss                  second
+#define pb                  push_back
+#define all(x)              x.begin(), x.end()
+#define sz(x)               (int)(x).size()
+
+#define yes                 cout<<"YES"<<endl
+#define no                  cout<<"NO"<<endl
+#define neg1                cout<<-1<<endl
+
+#define PI                  3.141592653589793238
+#define MIN                 INT_MIN
+#define MAX                 INT_MAX
+#define INF                 LONG_LONG_MAX
+#define MOD                 1000000007
+#define LLM                 1000000000000000007
+
+ll factorial(ll n)              { if(n==0) return 1; ll res = 1; for (ll i = 2; i <= n; i++) res = res * i; return res; }
+ll nPr(ll n, ll r)              { return factorial(n) / factorial(n - r); }
+ll nCr(ll n, ll r)              { return factorial(n) / (factorial(r) * factorial(n - r));}
+ll gcd(ll a, ll b)              { if (b == 0) return a; return gcd(b, a % b); }
+ll lcm(ll a, ll b)              { return (a * b) / gcd(a, b);}
+ull mypow(ull a, ull b)         { ull ans = 1; a%=MOD; while(b){ if (b&1) ans = (ans*a) % MOD; a = (a*a) % MOD; b >>= 1; } return ans; }
+bool isPrime(ll n)              { if(n <= 1) return false; for(ll i = 2; i*i <= n; i++) if(n % i == 0) return false; return true; }
+
+#ifndef ONLINE_JUDGE
+#define dbg(x) cerr << #x <<" "; _print(x); cerr << endl;
+#define dbgin(x) cerr << #x <<" "; _print(x); cerr << ";"<<endl;
+#else
+#define dbg(x)
+#define dbgin(x)
+#endif
+
+void _print(int t) {cerr << t;}void _print(string t) {cerr << t;}void _print(char t) {cerr << t;}
+void _print(long double t) {cerr << t;}void _print(double t) {cerr << t;}void _print(unsigned ll t) {cerr << t;}
+template <class T, class V> void _print(pair <T, V> p);
+template <class T> void _print(vector <T> v);template <class T> void _print(set <T> v);
+template <class T, class V> void _print(map <T, V> v);template <class T> void _print(multiset <T> v);
+template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.first); cerr << ","; _print(p.second); cerr << "}";}
+template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(unordered_set <T> v) {cerr<<"[ "; for(T i : v) {_print(i); cerr<<" ";} cerr<<"]";}
+template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T, class V> void _print(multimap <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";} 
+template <class T, class V> void _print(unordered_map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void solve()
+{
+    int n;
+    cin>>n;
+    vector<pair<int,int>>a;
+    vector<int>b(n);
+    for(int i=0; i<n; ++i)
+    {
+        int x;
+        cin>>x;
+        a.pb({x,i});
+    }
+    for(auto &i:b) cin>>i;
+    sort(all(a));
+    for(auto x:a)
+        cout<<x.ff<<" ";
+    cout<<endl;
+    for(int i=0; i<n; ++i)
+        cout<<b[a[i].ss]<<" ";
+    cout<<endl;
+}
+
+int32_t main()
+{
+    FAST_IO;
+    int TC = 1;
+    cin >> TC;
+    while (TC--) 
+        solve();
+}

Codes/1927 A - Make it White/1927A.cpp

@@ -0,0 +1,78 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define FAST_IO             (ios_base:: sync_with_stdio(false),cin.tie(NULL));
+
+#define int                 long long
+#define ll                  long long
+#define ull                 unsigned long long
+#define endl                '\n'
+#define ff                  first
+#define ss                  second
+#define pb                  push_back
+#define all(x)              x.begin(), x.end()
+#define sz(x)               (int)(x).size()
+
+#define yes                 cout<<"YES"<<endl
+#define no                  cout<<"NO"<<endl
+#define neg1                cout<<-1<<endl
+
+#define PI                  3.141592653589793238
+#define MIN                 INT_MIN
+#define MAX                 INT_MAX
+#define INF                 LONG_LONG_MAX
+#define MOD                 1000000007
+#define LLM                 1000000000000000007
+
+ll factorial(ll n)              { if(n==0) return 1; ll res = 1; for (ll i = 2; i <= n; i++) res = res * i; return res; }
+ll nPr(ll n, ll r)              { return factorial(n) / factorial(n - r); }
+ll nCr(ll n, ll r)              { return factorial(n) / (factorial(r) * factorial(n - r));}
+ll gcd(ll a, ll b)              { if (b == 0) return a; return gcd(b, a % b); }
+ll lcm(ll a, ll b)              { return (a * b) / gcd(a, b);}
+ull mypow(ull a, ull b)         { ull ans = 1; a%=MOD; while(b){ if (b&1) ans = (ans*a) % MOD; a = (a*a) % MOD; b >>= 1; } return ans; }
+bool isPrime(ll n)              { if(n <= 1) return false; for(ll i = 2; i*i <= n; i++) if(n % i == 0) return false; return true; }
+
+#ifndef ONLINE_JUDGE
+#define dbg(x) cerr << #x <<" "; _print(x); cerr << endl;
+#define dbgin(x) cerr << #x <<" "; _print(x); cerr << ";"<<endl;
+#else
+#define dbg(x)
+#define dbgin(x)
+#endif
+
+void _print(int t) {cerr << t;}void _print(string t) {cerr << t;}void _print(char t) {cerr << t;}
+void _print(long double t) {cerr << t;}void _print(double t) {cerr << t;}void _print(unsigned ll t) {cerr << t;}
+template <class T, class V> void _print(pair <T, V> p);
+template <class T> void _print(vector <T> v);template <class T> void _print(set <T> v);
+template <class T, class V> void _print(map <T, V> v);template <class T> void _print(multiset <T> v);
+template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.first); cerr << ","; _print(p.second); cerr << "}";}
+template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(unordered_set <T> v) {cerr<<"[ "; for(T i : v) {_print(i); cerr<<" ";} cerr<<"]";}
+template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T, class V> void _print(multimap <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";} 
+template <class T, class V> void _print(unordered_map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void solve()
+{
+    int n;
+    string s;
+    cin>>n>>s;
+    int i=0, j=sz(s)-1;
+    while(s[i]=='W')
+        i++;
+    while(s[j]=='W')
+        j--;
+    cout<<j-i+1<<endl;
+}
+
+int32_t main()
+{
+    FAST_IO;
+    int TC = 1;
+    cin >> TC;
+    while (TC--) 
+        solve();
+}

Codes/1927 B - Following the String/1927B.cpp

@@ -0,0 +1,98 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define FAST_IO             (ios_base:: sync_with_stdio(false),cin.tie(NULL));
+
+#define int                 long long
+#define ll                  long long
+#define ull                 unsigned long long
+#define endl                '\n'
+#define ff                  first
+#define ss                  second
+#define pb                  push_back
+#define all(x)              x.begin(), x.end()
+#define sz(x)               (int)(x).size()
+
+#define yes                 cout<<"YES"<<endl
+#define no                  cout<<"NO"<<endl
+#define neg1                cout<<-1<<endl
+
+#define PI                  3.141592653589793238
+#define MIN                 INT_MIN
+#define MAX                 INT_MAX
+#define INF                 LONG_LONG_MAX
+#define MOD                 1000000007
+#define LLM                 1000000000000000007
+
+ll factorial(ll n)              { if(n==0) return 1; ll res = 1; for (ll i = 2; i <= n; i++) res = res * i; return res; }
+ll nPr(ll n, ll r)              { return factorial(n) / factorial(n - r); }
+ll nCr(ll n, ll r)              { return factorial(n) / (factorial(r) * factorial(n - r));}
+ll gcd(ll a, ll b)              { if (b == 0) return a; return gcd(b, a % b); }
+ll lcm(ll a, ll b)              { return (a * b) / gcd(a, b);}
+ull mypow(ull a, ull b)         { ull ans = 1; a%=MOD; while(b){ if (b&1) ans = (ans*a) % MOD; a = (a*a) % MOD; b >>= 1; } return ans; }
+bool isPrime(ll n)              { if(n <= 1) return false; for(ll i = 2; i*i <= n; i++) if(n % i == 0) return false; return true; }
+
+#ifndef ONLINE_JUDGE
+#define dbg(x) cerr << #x <<" "; _print(x); cerr << endl;
+#define dbgin(x) cerr << #x <<" "; _print(x); cerr << ";"<<endl;
+#else
+#define dbg(x)
+#define dbgin(x)
+#endif
+
+void _print(int t) {cerr << t;}void _print(string t) {cerr << t;}void _print(char t) {cerr << t;}
+void _print(long double t) {cerr << t;}void _print(double t) {cerr << t;}void _print(unsigned ll t) {cerr << t;}
+template <class T, class V> void _print(pair <T, V> p);
+template <class T> void _print(vector <T> v);template <class T> void _print(set <T> v);
+template <class T, class V> void _print(map <T, V> v);template <class T> void _print(multiset <T> v);
+template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.first); cerr << ","; _print(p.second); cerr << "}";}
+template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(unordered_set <T> v) {cerr<<"[ "; for(T i : v) {_print(i); cerr<<" ";} cerr<<"]";}
+template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T, class V> void _print(multimap <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";} 
+template <class T, class V> void _print(unordered_map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void solve()
+{
+    int n;
+    cin>>n;
+    string s;
+    map<char,int>m;
+    char c='a';
+    for(int i=0; i<n; ++i)
+    {
+        int x;
+        cin>>x;
+        if(x==0)
+        {
+            s.pb(c);
+            m[c]++;
+            c++;
+        }
+        else
+        {
+            for(auto it:m)
+            {
+                if(it.ss==x)
+                {
+                    s.pb(it.ff);
+                    m[it.ff]++;
+                    break;
+                }
+            }
+        }
+    }
+    cout<<s<<endl;
+}
+
+int32_t main()
+{
+    FAST_IO;
+    int TC = 1;
+    cin >> TC;
+    while (TC--) 
+        solve();
+}

Codes/1927 C - Choose the Different Ones/1927C.cpp

@@ -0,0 +1,105 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define FAST_IO             (ios_base:: sync_with_stdio(false),cin.tie(NULL));
+
+#define int                 long long
+#define ll                  long long
+#define ull                 unsigned long long
+#define endl                '\n'
+#define ff                  first
+#define ss                  second
+#define pb                  push_back
+#define all(x)              x.begin(), x.end()
+#define sz(x)               (int)(x).size()
+
+#define yes                 cout<<"YES"<<endl
+#define no                  cout<<"NO"<<endl
+#define neg1                cout<<-1<<endl
+
+#define PI                  3.141592653589793238
+#define MIN                 INT_MIN
+#define MAX                 INT_MAX
+#define INF                 LONG_LONG_MAX
+#define MOD                 1000000007
+#define LLM                 1000000000000000007
+
+ll factorial(ll n)              { if(n==0) return 1; ll res = 1; for (ll i = 2; i <= n; i++) res = res * i; return res; }
+ll nPr(ll n, ll r)              { return factorial(n) / factorial(n - r); }
+ll nCr(ll n, ll r)              { return factorial(n) / (factorial(r) * factorial(n - r));}
+ll gcd(ll a, ll b)              { if (b == 0) return a; return gcd(b, a % b); }
+ll lcm(ll a, ll b)              { return (a * b) / gcd(a, b);}
+ull mypow(ull a, ull b)         { ull ans = 1; a%=MOD; while(b){ if (b&1) ans = (ans*a) % MOD; a = (a*a) % MOD; b >>= 1; } return ans; }
+bool isPrime(ll n)              { if(n <= 1) return false; for(ll i = 2; i*i <= n; i++) if(n % i == 0) return false; return true; }
+
+#ifndef ONLINE_JUDGE
+#define dbg(x) cerr << #x <<" "; _print(x); cerr << endl;
+#define dbgin(x) cerr << #x <<" "; _print(x); cerr << ";"<<endl;
+#else
+#define dbg(x)
+#define dbgin(x)
+#endif
+
+void _print(int t) {cerr << t;}void _print(string t) {cerr << t;}void _print(char t) {cerr << t;}
+void _print(long double t) {cerr << t;}void _print(double t) {cerr << t;}void _print(unsigned ll t) {cerr << t;}
+template <class T, class V> void _print(pair <T, V> p);
+template <class T> void _print(vector <T> v);template <class T> void _print(set <T> v);
+template <class T, class V> void _print(map <T, V> v);template <class T> void _print(multiset <T> v);
+template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.first); cerr << ","; _print(p.second); cerr << "}";}
+template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(unordered_set <T> v) {cerr<<"[ "; for(T i : v) {_print(i); cerr<<" ";} cerr<<"]";}
+template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T, class V> void _print(multimap <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";} 
+template <class T, class V> void _print(unordered_map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void solve()
+{
+    int n,m,k;
+    cin>>n>>m>>k;
+    set<int>a,b,ans;
+    for(int i=0; i<n; ++i)
+    {
+        int x;
+        cin>>x;
+        a.insert(x);
+    }
+    for(int i=0; i<m; ++i)
+    {
+        int x;
+        cin>>x;
+        b.insert(x);
+    }
+    int ct1=0,ct2=0;
+    for(auto x:a)
+    {
+        if(x<=k)
+        {    
+            ct1++;
+            ans.insert(x);
+        }
+    }
+    for(auto x:b)
+    {
+        if(x<=k)
+        {    
+            ct2++;
+            ans.insert(x);
+        }
+    }
+    if(sz(ans)==k && ct1>=k/2 && ct2>=k/2)
+        yes;
+    else
+        no;
+}
+
+int32_t main()
+{
+    FAST_IO;
+    int TC = 1;
+    cin >> TC;
+    while (TC--) 
+        solve();
+}

Codes/1927 D - Find the Different Ones!/1927D.cpp

@@ -0,0 +1,106 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+#define FAST_IO             (ios_base:: sync_with_stdio(false),cin.tie(NULL));
+
+#define int                 long long
+#define ll                  long long
+#define ull                 unsigned long long
+#define endl                '\n'
+#define ff                  first
+#define ss                  second
+#define pb                  push_back
+#define all(x)              x.begin(), x.end()
+#define sz(x)               (int)(x).size()
+
+#define yes                 cout<<"YES"<<endl
+#define no                  cout<<"NO"<<endl
+#define neg1                cout<<-1<<endl
+
+#define PI                  3.141592653589793238
+#define MIN                 INT_MIN
+#define MAX                 INT_MAX
+#define INF                 LONG_LONG_MAX
+#define MOD                 1000000007
+#define LLM                 1000000000000000007
+
+ll factorial(ll n)              { if(n==0) return 1; ll res = 1; for (ll i = 2; i <= n; i++) res = res * i; return res; }
+ll nPr(ll n, ll r)              { return factorial(n) / factorial(n - r); }
+ll nCr(ll n, ll r)              { return factorial(n) / (factorial(r) * factorial(n - r));}
+ll gcd(ll a, ll b)              { if (b == 0) return a; return gcd(b, a % b); }
+ll lcm(ll a, ll b)              { return (a * b) / gcd(a, b);}
+ull mypow(ull a, ull b)         { ull ans = 1; a%=MOD; while(b){ if (b&1) ans = (ans*a) % MOD; a = (a*a) % MOD; b >>= 1; } return ans; }
+bool isPrime(ll n)              { if(n <= 1) return false; for(ll i = 2; i*i <= n; i++) if(n % i == 0) return false; return true; }
+
+#ifndef ONLINE_JUDGE
+#define dbg(x) cerr << #x <<" "; _print(x); cerr << endl;
+#define dbgin(x) cerr << #x <<" "; _print(x); cerr << ";"<<endl;
+#else
+#define dbg(x)
+#define dbgin(x)
+#endif
+
+void _print(int t) {cerr << t;}void _print(string t) {cerr << t;}void _print(char t) {cerr << t;}
+void _print(long double t) {cerr << t;}void _print(double t) {cerr << t;}void _print(unsigned ll t) {cerr << t;}
+template <class T, class V> void _print(pair <T, V> p);
+template <class T> void _print(vector <T> v);template <class T> void _print(set <T> v);
+template <class T, class V> void _print(map <T, V> v);template <class T> void _print(multiset <T> v);
+template <class T, class V> void _print(pair <T, V> p) {cerr << "{"; _print(p.first); cerr << ","; _print(p.second); cerr << "}";}
+template <class T> void _print(vector <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(set <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(multiset <T> v) {cerr << "[ "; for (T i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T> void _print(unordered_set <T> v) {cerr<<"[ "; for(T i : v) {_print(i); cerr<<" ";} cerr<<"]";}
+template <class T, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+template <class T, class V> void _print(multimap <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";} 
+template <class T, class V> void _print(unordered_map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void solve()
+{
+    int n;
+    cin>>n;
+    vector<int>v(n),pre(n);
+    for(auto &i:v)  cin>>i;
+    vector<pair<int,int>>ind(n);
+    pre[0]=0;
+
+    for(int i=1; i<n; ++i)
+    {
+        if(v[i]!=v[i-1])
+        {
+            pre[i]=pre[i-1]+1;
+            ind[i]={i-1,i};
+        }
+        else
+        {
+            pre[i]=pre[i-1];
+            ind[i]={ind[i-1].ff,i};
+        }
+        
+    }
+    int q;
+    cin>>q;
+    while(q--)
+    {
+        int l,r;
+        cin>>l>>r;
+        l--,r--;
+        int ans=pre[r]-pre[l];
+        if(ans)
+        {
+            cout<<ind[r].ff+1<<" "<<ind[r].ss+1<<endl;
+        }
+        else
+            cout<<-1<<" "<<-1<<endl;
+    }
+    cout<<endl;
+}
+
+int32_t main()
+{
+    FAST_IO;
+    int TC = 1;
+    cin >> TC;
+    while (TC--) 
+        solve();
+}

Readme.md

@@ -244,14 +244,20 @@ This repository contains my solutions of Codeforces problems. They are in C++ la
 | 232 | 1916 D | Mathematical Problem | [Question](https://codeforces.com/problemset/problem/1916/D) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1916%20D%20-%20Mathematical%20Problem)
 | 233 | 1917 A | Least Product | [Question](https://codeforces.com/problemset/problem/1917/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1917%20A%20-%20Least%20Product)
 | 234 | 1917 B | Erase First or Second Letter | [Question](https://codeforces.com/problemset/problem/1917/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1917%20B%20-%20Erase%20First%20or%20Second%20Letter)
-| 235 | 1919 A | Wallet Exchange | [Question](https://codeforces.com/problemset/problem/1919/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1919%20A%20-%20Wallet%20Exchange)
+| 235 | 1918 A | Brick Wall | [Question](https://codeforces.com/problemset/problem/1918/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1918%20A%20-%20Brick%20Wall)
-| 236 | 1919 B | Plus-Minus Split | [Question](https://codeforces.com/problemset/problem/1919/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1919%20B%20-%20Plus-Minus%20Split)
+| 236 | 1918 B | Minimize Inversions | [Question](https://codeforces.com/problemset/problem/1918/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1918%20B%20-%20Minimize%20Inversions)
-| 237 | 1920 A | Satisfying Constraints | [Question](https://codeforces.com/problemset/problem/1920/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1920%20A%20-%20Satisfying%20Constraints)
+| 237 | 1919 A | Wallet Exchange | [Question](https://codeforces.com/problemset/problem/1919/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1919%20A%20-%20Wallet%20Exchange)
-| 238 | 1921 A | Square | [Question](https://codeforces.com/problemset/problem/1921/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1921%20A%20-%20Square)
+| 238 | 1919 B | Plus-Minus Split | [Question](https://codeforces.com/problemset/problem/1919/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1919%20B%20-%20Plus-Minus%20Split)
-| 239 | 1921 B | Arranging Cats | [Question](https://codeforces.com/problemset/problem/1921/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1921%20B%20-%20Arranging%20Cats)
+| 239 | 1920 A | Satisfying Constraints | [Question](https://codeforces.com/problemset/problem/1920/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1920%20A%20-%20Satisfying%20Constraints)
-| 240 | 1921 C | Sending Messages | [Question](https://codeforces.com/problemset/problem/1921/C) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1921%20C%20-%20Sending%20Messages)
+| 240 | 1920 B | Summation Game | [Question](https://codeforces.com/problemset/problem/1920/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1920%20B%20-%20Summation%20Game)
-| 241 | 1921 D | Very Different Array | [Question](https://codeforces.com/problemset/problem/1921/D) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1921%20D%20-%20Very%20Different%20Array)
+| 241 | 1921 A | Square | [Question](https://codeforces.com/problemset/problem/1921/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1921%20A%20-%20Square)
-| 242 | 19020 B | Summation Game | [Question](https://codeforces.com/problemset/problem/19020/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/19020%20B%20-%20Summation%20Game)
+| 242 | 1921 B | Arranging Cats | [Question](https://codeforces.com/problemset/problem/1921/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1921%20B%20-%20Arranging%20Cats)
+| 243 | 1921 C | Sending Messages | [Question](https://codeforces.com/problemset/problem/1921/C) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1921%20C%20-%20Sending%20Messages)
+| 244 | 1921 D | Very Different Array | [Question](https://codeforces.com/problemset/problem/1921/D) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1921%20D%20-%20Very%20Different%20Array)
+| 245 | 1927 A | Make it White | [Question](https://codeforces.com/problemset/problem/1927/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1927%20A%20-%20Make%20it%20White)
+| 246 | 1927 B | Following the String | [Question](https://codeforces.com/problemset/problem/1927/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1927%20B%20-%20Following%20the%20String)
+| 247 | 1927 C | Choose the Different Ones | [Question](https://codeforces.com/problemset/problem/1927/C) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1927%20C%20-%20Choose%20the%20Different%20Ones)
+| 248 | 1927 D | Find the Different Ones! | [Question](https://codeforces.com/problemset/problem/1927/D) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1927%20D%20-%20Find%20the%20Different%20Ones!)