1120번 문자열

https://www.acmicpc.net/problem/1120

#include <iostream>
#include <queue>
#include <stack>
#include <cstdio>
#include <vector>
#include <cstring>
#include <string>
#include <math.h>
#include <algorithm>
#include <map>
 
using namespace std;
 
string A, B;
 
int main(void)
{
    cin >> A;
    cin >> B;
 
    int diff = 0;
 
    if (A.length() == B.length())
    {
        for (int i = 0; i < A.length(); i++)
        {
            if (A.at(i) != B.at(i)) ++diff;
        }
    }
    else
    {
        diff = 100;    
 
        for (int i = 0; i < B.length(); i++)
        {
            int a = 0, b = i, d = 0;
 
            if (i + A.length() > B.length()) break;
 
            while (a < A.length())
            {
                if (A.at(a) != B.at(b)) ++d;
                        
                ++a;
                ++b;            
            }
            
            diff = min(diff, d);
        }
    }
 
    printf("%d\n", diff);
 
    return 0;
}