题解 | 字符串操作

#include<iostream>
using namespace std;
int main(){
    int n,m;
    cin >> n >> m;
    string s;
    while(n>0){
        char c;
        cin >> c;
        s.push_back(c);
        n--;
    }
    for(int i=0;i<m;i++){
        int n1,n2;
        char x,y;
        cin >> n1 >> n2 >> x >> y;
        for(int j=n1-1;j<=n2-1;j++){
            if(s[j]==x)s[j]=y;
        }
    }
    cout << s << endl;
    return 0;
}