Submission #1128969

#	Time	Username	Problem	Language	Result	Execution time	Memory
1128969		ivaziva	Bliskost (COI23_bliskost)	C++20	100 / 100	148 ms	13692 KiB

Main

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("fast-math")
#pragma GCC target("tune=native")
#include <bits/stdc++.h>

using namespace std;

constexpr int MAXN = 1000001;
constexpr int MOD = 26;

int n, q;
string s1, s2;
int x[MAXN], y[MAXN];

inline int mod26(int value) {
    return (value % MOD + MOD) % MOD;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    cin >> n >> q >> s1 >> s2;

    y[1] = mod26(s2[0] - s1[0]);
    x[1] = y[1];
    for (int i = 2; i <= n; ++i) {
        y[i] = mod26(s2[i - 1] - s1[i - 1]);
        x[i] = mod26(y[i] - x[i - 1]);
    }

    cout << (x[n - 1] == y[n] ? "da" : "ne") << '\n';

    while (q--) {
        int pos; char c;
        cin >> pos >> c;

        if (pos == n) {
            s1[n - 1] = c;
            y[n] = mod26(s2[n - 1] - s1[n - 1]);
        } else {
            int delta = mod26(s1[pos - 1] - c);
            s1[pos - 1] = c;

            if ((n - 1 - pos) % 2 == 0)
                x[n - 1] = mod26(x[n - 1] + delta);
            else
                x[n - 1] = mod26(x[n - 1] - delta);
        }

        cout << (x[n - 1] == y[n] ? "da" : "ne") << '\n';
    }

    return 0;
}

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