题解 | 字符串操作

#include <ios>
#include <iostream>
using namespace std;

int main() {
    int n, m, l, r;
    string s;
    char c1, c2;
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> m >> s;
    while (m) {
        cin >> l >> r >> c1 >> c2;
        for (int i = l - 1; i < r; i++) {
            if (s[i] == c1) {
                s[i] = c2;
            }
        }
        m--;
    }
    cout << s;
}
// 64 位输出请用 printf("%lld")