题解 | #截取字符串#

#include<bits/stdc++.h>
using namespace std;
int main () {
    string str;
    int n;
    while(cin>>str>>n) {
        cout<<str.substr(0,n)<<endl;        //截取字符串[0,n)位，长度为n的字符串
    }
    return 0;
}