Submission #431697

#	Time	Username	Problem	Language	Result	Execution time	Memory
431697		sikamax2019	Palindromes (APIO14_palindrome)	C++14	0 / 100	1 ms	204 KiB

palindrome

#include <bits/stdc++.h>
using namespace std;

int longestPalSubstr(string str)
{
	int n = str.size();
	bool table[n][n];

	memset(table, 0, sizeof(table));

	int maxLength = 1;

	for (int i = 0; i < n; ++i)
		table[i][i] = true;

	int start = 0;
	for (int i = 0; i < n - 1; ++i) {
		if (str[i] == str[i + 1]) {
			table[i][i + 1] = true;
			start = i;
			maxLength = 2;
		}
	}

	for (int k = 3; k <= n; ++k) {

		for (int i = 0; i < n - k + 1; ++i) {

			int j = i + k - 1;
			if (table[i + 1][j - 1] && str[i] == str[j]) {
				table[i][j] = true;

				if (k > maxLength) {
					start = i;
					maxLength = k;
				}
			}
		}
	}
	return maxLength;
}

int main()
{
	freopen("palindrome.in", "r", stdin);
	freopen("palindrome.out", "w", stdout);

	string str;
	cin>>str;
	cout << longestPalSubstr(str);
	return 0;
}

Compilation message (stderr)

palindrome.cpp: In function 'int longestPalSubstr(std::string)':
palindrome.cpp:16:6: warning: variable 'start' set but not used [-Wunused-but-set-variable]
   16 |  int start = 0;
      |      ^~~~~
palindrome.cpp: In function 'int main()':
palindrome.cpp:45:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |  freopen("palindrome.in", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
palindrome.cpp:46:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |  freopen("palindrome.out", "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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