Submission #854237

#	Time	Username	Problem	Language	Result	Execution time	Memory
854237		Trisanu_Das	Bliskost (COI23_bliskost)	C++17	100 / 100	242 ms	24408 KiB

Main

#include <bits/stdc++.h>
using namespace std;
 
int N, Q;
string s, t;
 
struct segtree{
	int st[1000005 << 1];
	void upd(int p, int v){
		for(p += 1000005, st[p] = v, p >>= 1; p > 0; p >>= 1) st[p] = st[p << 1] + st[p << 1|1];
	}
	int que(int l, int r){
		int res = 0;
		for(l += 1000005, r += 1000005 + 1; l < r; l >>= 1, r >>= 1){
			if(l & 1) res += st[l++];
			if(r & 1) res += st[--r];
		}
		return res;
	}
} S;
 
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin >> N >> Q >> s >> t;
	for(int i = N - 1; i >= 0; i--){
		int x = ((int) t[i] - (int) s[i] + 26) % 26;
		if((N - 1 - i) & 1) S.upd(i, -x);
		else S.upd(i, x);
	}
	if(S.que(0, N - 1) % 26 == 0) cout << "da\n";
	else cout << "ne\n";
	for(int i = 0; i < Q; i++){
		int p; char c; cin >> p >> c; p--;
		int x = ((int) t[p] - (int) c + 26) % 26;
		if((N - p - 1) & 1) S.upd(p, -x);
		else S.upd(p, x);
		s[p] = c;
		if(S.que(0, N - 1) % 26 == 0) cout << "da\n";
		else cout << "ne\n";
	}
}

• Subtask 1: 7 / 7
• Subtask 2: 8 / 8
• Subtask 3: 13 / 13
• Subtask 4: 12 / 12
• Subtask 5: 17 / 17
• Subtask 6: 43 / 43