#include <bits/stdc++.h> using namespace std; #define int long long void f(){ #ifndef ONLINE_JUDGE freopen("in.txt", "r", stdin); freopen("out.txt", "w", stdout); #endif } signed main(){ ios_base::sync_with_stdio(false); cin.tie(0); //f(); int n, q; cin >>n >> q; vector<int> a(n); int sb=0, sa=0; string s, t; cin >> s>> t; for(int i=0; i<n; i++){ if((s[i]-'a')%2) sa++, a[i]=1; if((t[i]-'a')%2) sb++; } if(sa%2!=sb%2) cout<<"ne"<<"\n"; else cout<<"da"<<"\n"; while(q--){ int p; cin >> p; p--; char x; cin >> x; x--; x-='a'; if(x%2!=a[p]){ sa++; a[p]^=1; } if(sa%2!=sb%2) cout<<"ne"<<"\n"; else cout<<"da"<<"\n"; } }

Main.cpp: In function 'void f()':
Main.cpp:8:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |  freopen("in.txt", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:9:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 |  freopen("out.txt", "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~