题解 | 牛牛的替换

#include <stdio.h>

int main() {
	int n = 0;
	char instead[4] = { ' ' };
	scanf("%d", &n);
	for (int i = 0; i < 4; i++) {
		getchar();
		scanf("%c", &instead[i]);
	}
	getchar();
	for (int i = 0; i < n; i++) {
		char before = ' ';
		scanf("%c", &before);
		if (before == instead[0]) {
			before = instead[1];
		}
		if (before == instead[2]) {
			before = instead[3];
		}
		printf("%c", before);
	}
	return 0;
}