题解 | 字符串操作

#include <stdio.h>

int main() {
    int n, m;
    scanf("%d %d", &n, &m);
    char str[n + 1];
    scanf("%s", str);
    int l, r;
    char c1, c2;
    for (int i = 0; i < m; ++i) {
        scanf("%d %d %c %c", &l, &r, &c1, &c2);
        for (int j = l - 1; j < r; ++j) {
            if (str[j] == c1) {
                str[j] = c2;
            }
        }
    }
    puts(str);
    return 0;
}