#include <stdio.h> 借鉴了一种认为比较好的代码 int main() { int n, m, l, r; char s[1000] = {0}, c1, c2; scanf("%d %d\n%s", &n, &m, &s); for (int i = 0; i < m; i++) { scanf("%d %d %c %c\n", &l, &r, &c1, &c2); for (int j = l; j <= r; j++) { if (s[j - 1] == c1) s[j - 1] = c2; } } printf("%s", s); return 0; }