题解 | #查找两个字符串a,b中的最长公共子串#

#include <iostream>
#include <string>
using namespace std;

void str_Changed(string &st1, string &st2){
    int str_len1 = st1.size();
    int str_len2 = st2.size();
    if(str_len1 < str_len2){
        string temp = st1;
        st1 = st2;
        st2 = temp;
    }
}

int main(){
    string str1;
    string str2;
    while(cin >> str1 >> str2){
        str_Changed(str1,str2);//确保str1比str2长
        int len1 = str1.size();
        int len2 = str2.size();
        int cnt = 0;
        int maxm = 0;
        int index = 0;
        for(int i = 0; i < len2; i++){
            int temp = i;
            cnt = 0;
            for(int j = 0; j < len1; j++){
                if(str1[j] == str2[temp]){
                    cnt++;
                    temp++;
                }
                else if(cnt > maxm){
                    maxm = cnt;
                    index = i;
                    cnt = 0;
                    temp = i;
                }
                else if(cnt <= maxm){
                    cnt = 0;
                    temp = i;
                }
            }

        }
           for(int i = index; i < index + maxm; i++){
                cout << str2[i];
            }
    }
}