12605 - Rebranding

#include <stdio.h>

int main(){
    char str[200001], buf[26], a, b, look[26];
    int n, m;
    scanf("%d%d%s", &n, &m, str);
    for(int i = 0; i < 26; ++i){
        buf[i] = i;
        //printf("%d", buf[i]);
    }
    while(m--){
        scanf(" %c %c", &a, &b);
        int temp = buf[a -'a'];
        buf[a - 'a'] = buf[b - 'a'];
        buf[b - 'a'] = temp;
    }
    /*for(int i = 0; i < 26; ++i){
        printf("%d ", buf[i]);
    }
    */
    for(int i = 0; i < 26; ++i){
        look[buf[i]] = i + 'a';
    }
    for(m = 0 ; m < n; ++m){
        str[m] = look[str[m] - 'a'];
    }
    puts(str);
    return 0;
}