字符串区间比较

#include<iostream>
using namespace std;
int main()
{
	int i, j,n;
	string s1, s2,a1,a2;
	cin >> i >> j;
	cin >> s1 >> s2;
	a1 = s1[i-1];
	a2 = s2[i-1];
	for (n = i-1; n < j; n++)
	{
		a1 += s1[n];
		a2 += s2[n];
	}
	if (a1 == a2)
		cout << "yes" << endl;
	else
		cout << "no" << endl;
	return 0;
}