题解 | #字符串操作#

#include <stdio.h>

int main() {
    int a, b;
    scanf("%d %d", &a, &b);
    char arr[a + 1];
    scanf("%s", arr);
    int arr1[4];
    for (int i = 0; i < b; i++) {
        for (int n = 0; n < 4; n++) {
            if (n < 2)
                scanf("%d", arr1 + n);
            else {
                getchar();
                arr1[n] = getchar();
            }
        }
        for (int j = arr1[0] - 1; j < arr1[1]; j++) {
            if (arr[j] == arr1[2]) {
                arr[j] = arr1[3];
            }
        }
    }
    printf("%s\n", arr);
    return 0;
}