求最长回文字符串（马拉车算法）#include <bits/stdc++.h> using namespace std; #define ll long long const ll int maxn = 3e7+10; const l

#include <bits/stdc++.h> #define INF 0x3f3f3f3f #define ll __int64 #define speed(x) ios::sync_with_stdio(false), cin.