【题解】求A-B字符串

#include<bits/stdc++.h>
#define INF 0x3f3f3f3f
#define N 10001
using namespace std;
string s1,s2,x;
int main(){
	s1="abcdedfg";
	s2=s1.substr(2,3);
	cout<<s2<<endl;
	x="d";
	int ind = s1.find(x);
	s1.erase(ind,1);
	cout<<s1<<endl;
	return 0;
}