思路：

只要列舉最終匹配的子串是從s中的哪個字元開始的就好了，並記錄最小值。

程式碼：

#include <iostream>
#include <string.h>
using namespace std;
int main()
{
    // please define the C++ input here. For example: int a,b; cin>>a>>b;;
    // please finish the function body here.
    // please define the C++ output here. For example:cout<<____<<endl;
 

    string str1;
    string str2;
    cin>>str1;
    cin>>str2;
    int t = 0;
    int count = 0;
    if(str1.find(str2)!=str1.npos) {
        cout<<0<<endl;
        return 0;
    }
    int max_len = str1.length()-str2.length() + 1;
    int ret = max_len;
    for(int i = 0;i<max_len;i++)
    {
        
 
if(str1[i] != str2[0])
        {
            continue;
        }
        int temp = 0;
        int index_next = 1;
        for(int j = i+1;j<str1.length();j++)
        {
            if(str1[j]!=str2[index_next])
            {
                temp++;
            }else{
                index_next++;
            }
            
 
if(index_next==str2.length())
            {
                if(ret >temp)
                {
                    ret=temp;
                }
            }
        }
    }
    cout<<ret<<endl;
    return 0;
}