added 1851C

1851C Tiles Comeback/1851C.cpp

@@ -0,0 +1,110 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+// Short forms
+#define int                 long long
+#define ll                  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()
+
+// Outputs
+#define yes                 cout<<"YES"<<endl
+#define no                  cout<<"NO"<<endl
+
+// Constants
+#define PI                  3.141592653589793238
+#define INF                 LONG_LONG_MAX
+#define MOD                 1e9+7
+
+// Faster Input Output
+#define FAST_IO             (ios_base:: sync_with_stdio(false),cin.tie(NULL));
+
+// Maths
+ll fact(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 fact(n) / fact(n - r); }
+ll nCr(ll n, ll r)     { return fact(n) / (fact(r) * fact(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);}
+ll mypow(ll a, ll b)   { ll ans = 1; while(b){ if (b&1) ans = (ans*a) ; b /= 2; a = (a*a); } return ans; }
+bool isPrime(ll n)     { if(n <= 1) return false; for(ll i = 2; i <= sqrt(n); i++) if(n % i == 0) return false; return true; }
+
+//Debugging
+#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, class V> void _print(map <T, V> v) {cerr << "[ "; for (auto i : v) {_print(i); cerr << " ";} cerr << "]";}
+ 
+
+/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void solve()
+{
+    int n,k;
+    cin>>n>>k;
+    vector<int>v(n);
+    for(int i=0; i<n; ++i)
+        cin>>v[i];
+    if(v[0]==v[n-1])
+    {
+        int ct=count(all(v),v[0]);
+        if(ct<k)
+            no;
+        else
+            yes;
+    }
+    else
+    {
+        int ctx=0,cty=0,x=n,y=0;
+        for(int i=n-1; i>=0; --i)
+        {
+            if(v[i]==v[n-1])
+                cty++;
+            if(cty==k)
+            {
+                y=i;
+                break;
+            }
+        }
+        for(int i=0; i<n; ++i)
+        {
+            if(v[i]==v[0])
+                ctx++;
+            if(ctx==k)
+            {
+                x=i;
+                break;
+            }
+        }
+        if(x<y)
+            yes;
+        else
+            no;
+    }
+}
+
+int32_t main()
+{
+    FAST_IO;
+    int TC = 1;
+    cin >> TC;
+    while (TC--) 
+        solve();
+}

Readme.md

@@ -147,6 +147,7 @@ Feel free to check these codes out.
 | 1850D | Balanced Round | [Question](https://codeforces.com/problemset/problem/1850/D) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/blob/master/1850D%20Balanced%20Round/1850D.cpp)
 | 1851A | Escalator Conversations | [Question](https://codeforces.com/problemset/problem/1851/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/blob/master/1851A%20Escalator%20Conversations/1851A.cpp)
 | 1851B | Parity Sort | [Question](https://codeforces.com/problemset/problem/1851/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/blob/master/1851B%20Parity%20Sort/1851B.cpp)
+| 1851C | Tiles Comeback | [Question](https://codeforces.com/problemset/problem/1851/C) | [Solution]
 | 1853A | Desorting | [Question](https://codeforces.com/contest/1853/problem/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/blob/master/1853A%20Desorting/1853A.cpp)
 | 1855A | Dalton the Teacher | [Question](https://codeforces.com/contest/1855/problem/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/blob/master/1855A%20Dalton%20the%20Teacher/1855A.cpp)
 | 1856B | Good Arrays | [Question](https://codeforces.com/problemset/problem/1856/B) | [Solution]