feat: Add solutions for Codeforces problems 1968F, 1968G1

Codes/1968 F - Equal XOR Segments/1968F.cpp

@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define ll long long
+#define endl '\n'
+#define FAST (ios_base::sync_with_stdio(false), cin.tie(nullptr));
+ll pow(ll x,ll y,ll m=1e9+7){ll ans=1;x%=m;while(y){if(y&1)ans=(ans*x)%m;x=(x*x)%m;y>>=1;}return ans;}
+
+void solve()
+{
+    ll n, q;
+    cin >> n >> q;
+    vector<ll>v(n+1,0);
+    map<ll, vector<ll>> m;
+    m[0].push_back(0);
+    for(int i = 1; i <= n; ++i)
+    {
+        cin>>v[i];
+        v[i] ^= v[i-1];
+        m[v[i]].push_back(i);
+    }
+    while(q--)
+    {
+        ll l, r;
+        cin>>l>>r;
+        if(v[l-1]==v[r])
+        {
+            cout<<"YES\n";
+            continue;
+        }
+        auto &v1=m[v[r]], &v2=m[v[l-1]];
+        int it1=*lower_bound(v1.begin(), v1.end(), l);
+        int it2=*--lower_bound(v2.begin(), v2.end(), r);
+        if(it1<it2) cout<<"YES\n";
+        else    cout<<"NO\n";
+    }
+    cout<<endl;
+}
+
+signed main()
+{
+    FAST;
+    int TCS = 1;
+    cin >> TCS;
+    for (int TC = 1; TC <= TCS; ++TC)
+    {
+        // cout<<"Case "<<TC<<": ";
+        solve();
+    }
+}

Codes/1968 G1 - Division + LCP (easy version)/1968G1.cpp

@@ -0,0 +1,66 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define ll long long
+#define endl '\n'
+#define FAST (ios_base::sync_with_stdio(false), cin.tie(nullptr));
+ll pow(ll x,ll y,ll m=1e9+7){ll ans=1;x%=m;while(y){if(y&1)ans=(ans*x)%m;x=(x*x)%m;y>>=1;}return ans;}
+
+vector<int>Zfunc(string &str)
+{
+	int n=str.size();
+	vector<int>z(n);
+	int l=0,r=0;
+	for(int i=1;i<n;i++)
+    {
+		if(i<=r)  z[i]=min(r-i+1,z[i-l]);
+		while(i+z[i]<n&&str[z[i]]==str[i+z[i]])	z[i]++;
+		if(i+z[i]-1>r)
+        {
+			l=i;
+			r=i+z[i]-1;
+		}
+	}
+	return z;
+}
+
+void solve()
+{
+    int n, k;
+    string s;
+    cin>> n >> k >> k >> s;
+    vector<int>z = Zfunc(s);
+    ll low = 1, high = n, ans = 0;
+    while(low <= high)
+    {
+        ll mid = low + (high - low) / 2;
+        ll cnt = 1;
+        for(int i = mid;i < n;)
+        {
+		    if(z[i] >= mid)
+            {
+			    cnt++;
+			    i += mid;
+		    }
+            else i++;
+	    }
+        if(cnt >= k)
+        {
+            ans = mid;
+            low = mid+1;
+        }
+        else high = mid-1;
+    }
+    cout<<ans<<endl;
+}
+
+signed main()
+{
+    FAST;
+    int TCS = 1;
+    cin >> TCS;
+    for (int TC = 1; TC <= TCS; ++TC)
+    {
+        // cout<<"Case "<<TC<<": ";
+        solve();
+    }
+}

Readme.md

@@ -311,8 +311,10 @@ This repository contains my solutions of Codeforces problems. They are in C++ la
 | 299 | 1968 C | Assembly via Remainders | [Question](https://codeforces.com/problemset/problem/1968/C) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1968%20C%20-%20Assembly%20via%20Remainders)
 | 300 | 1968 D | Permutation Game | [Question](https://codeforces.com/problemset/problem/1968/D) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1968%20D%20-%20Permutation%20Game)
 | 301 | 1968 E | Cells Arrangement | [Question](https://codeforces.com/problemset/problem/1968/E) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1968%20E%20-%20Cells%20Arrangement)
-| 302 | 1969 A | Two Friends | [Question](https://codeforces.com/problemset/problem/1969/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1969%20A%20-%20Two%20Friends)
+| 302 | 1968 F | Equal XOR Segments | [Question](https://codeforces.com/problemset/problem/1968/F) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1968%20F%20-%20Equal%20XOR%20Segments)
-| 303 | 1969 B | Shifts and Sorting | [Question](https://codeforces.com/problemset/problem/1969/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1969%20B%20-%20Shifts%20and%20Sorting)
+| 303 | 1968 G1 | Division + LCP (easy version) | [Question](https://codeforces.com/problemset/problem/1968/G1) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1968%20G1%20-%20Division%20+%20LCP%20(easy%20version))
+| 304 | 1969 A | Two Friends | [Question](https://codeforces.com/problemset/problem/1969/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1969%20A%20-%20Two%20Friends)
+| 305 | 1969 B | Shifts and Sorting | [Question](https://codeforces.com/problemset/problem/1969/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1969%20B%20-%20Shifts%20and%20Sorting)