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;
int main() {
    string input1,input2;
    string LongStr,ShortStr;
    getline(cin, input1);getline(cin, input2);
    if(input1.size()<input2.size()){
        ShortStr = input1;
        LongStr = input2;
    }else{
        ShortStr = input2;
        LongStr = input1;
    }//因为输入没分长短，所以提前分好，下面可以根据短字符串来遍历
    int maxlen = 0;
    int startIndex = -1;
    for(int i=0;i<ShortStr.size();i++){
        for(int len =1;i+len<=ShortStr.size();len++){
           string substr = ShortStr.substr(i,len);
           if(LongStr.find(substr)!=string::npos){
            if(len>maxlen){
                maxlen = len;
                startIndex = i;
            }//在长串中寻找是否有相同子串，如果有就更新长度和起始下标
           }
        }
    }
    cout<<ShortStr.substr(startIndex,maxlen)<<endl;
    return 0;
}
// 64 位输出请用 printf("%lld")