Shortest palindrome

input/code.cpp: In function 'int shortest_palindrome(std::string)':
input/code.cpp:24:28: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   24 |         while (l >= 0 && r < n && s[l] == s[r])
      |                          ~~^~~
input/code.cpp:34:28: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   34 |         while (l >= 0 && r < n && s[l] == s[r])
      |                          ~~^~~

#include <bits/stdc++.h>

using namespace std;

#define debug(x) cerr << #x << ": " << x << endl;
#define ll long long
#define ull unsigned long long
#define vi vector<int>

int shortest_palindrome(string s) {
    int shortest_lenght = INT_MAX;
    size_t n = s.size();

    for (size_t i = 0; i < n; i++)
    {
        int l;
        int r;
        int odd_size = 1;
        int even_size = 0;
         
        // Find the longest odd length palindrome 
        // with center point as i 
        l = i-1; r = i+1;
        while (l >= 0 && r < n && s[l] == s[r])
        {
            odd_size += 2;
            l--;
            r++;
        }

        // Find the even length palindrome  
        // with center points as i-1 and i.
        l = i - 1; r = i;
        while (l >= 0 && r < n && s[l] == s[r])
        {
            even_size += 2;
            l--;
            r++;
        }

        if (odd_size > 1)  shortest_lenght = min(shortest_lenght, odd_size);
        if (even_size > 1) shortest_lenght = min(shortest_lenght, even_size);
    }

    return shortest_lenght == INT_MAX ? -1 : shortest_lenght;
}

int main() {
    string s;
    cin >> s;

    cout << shortest_palindrome(s) << endl;

    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

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Test 8

Verdict: ACCEPTED

Test 9

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Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: ACCEPTED

Test 51

Verdict: ACCEPTED

Test 52

Verdict: ACCEPTED

Test 53

Verdict: ACCEPTED

Test 54

Verdict: ACCEPTED

Test 55

Verdict: ACCEPTED

Test 56

Verdict: ACCEPTED

Test 57

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Test 58

Verdict: ACCEPTED

Test 59

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Test 60

Verdict: ACCEPTED

Test 61

Verdict: ACCEPTED

Test 62

Verdict: ACCEPTED

Test 63

Verdict: ACCEPTED

Test 64

Verdict: ACCEPTED

Test 65

Verdict: ACCEPTED

Test 66

Verdict: ACCEPTED

Test 67

Verdict: ACCEPTED

Test 68

Verdict: ACCEPTED