/* ID: 5ak0 PROG: LANG: C++11 */ #include <bits/stdc++.h> #define fr first #define sc second #define pb push_back #define mpr make_pair using namespace std; typedef long long ll; typedef pair<int, int> pii; const int INF = 1e9 + 7; const int N = 300000; string s; int ans; int calc(string str){ int n = str.size(); int dp[n][n]; memset(dp, 0, sizeof(dp)); bool P[n][n]; memset(P, false , sizeof(P)); for (int i= 0; i< n; i++) P[i][i] = true; for (int i=0; i<n-1; i++) { if (str[i] == str[i+1]) { P[i][i+1] = true; dp[i][i+1] = 1 ; } } for (int gap=2 ; gap<n; gap++){ for (int i=0; i<n-gap; i++){ int j = gap + i; if (str[i] == str[j] && P[i+1][j-1] ) P[i][j] = true; if (P[i][j] == true) dp[i][j] = dp[i][j-1] + dp[i+1][j] + 1 - dp[i+1][j-1]; else dp[i][j] = dp[i][j-1] + dp[i+1][j] - dp[i+1][j-1]; } } return dp[0][n-1] + n; } int main(){ cin >> s; ans = calc(s); for (int i = 0; i < s.size(); ++i){ char ch = s[i]; for (char j = 'a'; j <= 'z'; ++j){ s[i] = j; ans = max(ans, calc(s)); } s[i] = ch; } cout << ans; return 0; }

palinilap.cpp: In function 'int main()':
palinilap.cpp:57:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < s.size(); ++i){
                       ^