View Code of Problem 4062

#include <iostream>
#include <string>
#include <cmath>		
#include <algorithm>
#include <stack>
#include <vector>
#include <set>
#include <queue>
using namespace std;

int main()
{
	int i, j, flag, k;
	int n, m, t;
	string str;
	string s1, s2;
	cin >> n;
	while (n--)
	{
		cin >> s1 >> s2 >> k;
		for (i = 0; i < s1.size(); )
		{
			if (s1[i] == s2[i])
			{
				s1.erase(i, 1);
				s2.erase(i, 1);
			}
			else
				i++;
		}
		t = 0;
		flag = 1;
		for (j = 0; j < s1.size(); ++j)
		{
			if (s1[j] != s2[j])
			{
				int pos = s2.find(s2[j],j+1);
				if (pos == -1)
				{
					pos = s1.find(s2[j], j + 1);
					if (pos != -1)
					{
						swap(s1[j], s1[pos]);
						t++;
					}
					else
					{
						flag = 0;
						break;
					}
				}
				else
				{
					swap(s1[j], s2[pos]);
					t++;
				}
				
			}
		}
		if(flag==0)		
			cout << "NO" << endl;
		else if (t <= k)
			cout << "YES" << endl;
		else
			cout << "NO" << endl;
	}
	return 0;
}