Submission #34069

#	Time	Username	Problem	Language	Result	Execution time	Memory
34069		mohammad_kilani	Palindromes (APIO14_palindrome)	C++14	8 / 100	1000 ms	53404 KiB

palindrome

#include <bits/stdc++.h>
using namespace std;
#define mod 10000007
#define oo 2000000000
const int N = 10040;
int p = 107;
bitset < N > can[N] ;
int mp[10000100];
char s[N];

bool isprime(int num){
	if(num == 1) return false;
	for(int i=2;i*i<=num;i++) if(num % i == 0) return false;
	return true;
}

int main() {
	//freopen("in.txt","r",stdin);
	scanf("%s",s);
	int n = strlen(s);
	long long ans = 0 ;
	for(int i=0;i<n;i++){
		int idx = i;
		int idx2 = i;
		while(idx >= 0 && idx2 < n && s[idx] == s[idx2]){
			can[idx][idx2] = true;
			idx--;
			idx2++;
		}
		idx = i;
		idx2 = i + 1;
		while(idx >= 0 && idx2 < n && s[idx] == s[idx2]){
			can[idx][idx2] = true;
			idx--;
			idx2++;
		}
	}
	for(int i=0;i<n;i++){
		long long tmp = 0 ;
		long long po = 1;
		for(int j=i;j<n;j++){
			tmp+=(((long long)(s[j]-'a'+1) * po) % mod);
			tmp %= mod;
			po = ((long long)p * po) % mod;
			int cur = ++mp[tmp];
			if(can[i][j] && ans < ((long long)cur * (j-i+1))){
				ans = ((long long)cur * (j-i+1));
			}
		}
	}
	printf("%lld\n",ans);
	return 0;
}

Compilation message (stderr)

palindrome.cpp: In function 'int main()':
palindrome.cpp:19:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s",s);
               ^

• Subtask 1: 8 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 26
• Subtask 5: 0 / 27