版权声明:假装有个原创声明……虽然少许博文不属于完全原创,但也是自己辛辛苦苦总结的,转载请注明出处,感谢! https://blog.csdn.net/m0_37454852/article/details/88532820
#include <algorithm>
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <cstring>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
using namespace std;
const int MAX = 10000, INF = 1<<30;
string str, max_sub;
bool dp[MAX][MAX] = {0};
int main()
{
cin>>str;
if(str.size()) max_sub = str[0];
for(int i=0; i<(int)str.size(); i++)
{
dp[i][i] = 1;
if(i < (int)str.size()-1 && str[i] == str[i+1])
{
dp[i][i+1] = 1;
max_sub = str.substr(i, 2);
}
}
for(int L=3; L<=(int)str.size(); L++)
{
for(int i=0, j=i+L-1; j<(int)str.size(); i++, j++)
{
if(str[i] == str[j] && dp[i+1][j-1])
{
dp[i][j] = 1;
max_sub = str.substr(i, L);
}
else dp[i][j] = 0;
}
}
cout<<max_sub<<endl;
return 0;
}