Palindrome

input/code.cpp: In function 'int main(int, char**)':
input/code.cpp:16:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int mid = 0; mid + offset < input.length(); mid++) {
                                                       ^
input/code.cpp:25:61: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                     if (i + i + offset + 1 > largest.length()) {
                                                             ^

#include <algorithm>
#include <iostream>
#include <sstream>
#include <cstring>
int main(int argc, char **argv)
{
	using namespace std;
	ios::sync_with_stdio(0);
	string input;
	cin >> input;

    string largest = "";
    // offset is O or 1 for odd, and even sized palindromes.
    for (int offset = 0; offset <= 1; offset++) {

        for (int mid = 0; mid + offset < input.length(); mid++) {

            // max is the space between the mid and the end
            int max = input.length() - offset - mid;
            // ... unless the mid is closer to the beginning than the end.
            max = max > mid ? mid : max;

            for (int i = 0; i < max; i++) {
                if (input[mid - i] == input[mid + offset + i]) {
                    if (i + i + offset + 1 > largest.length()) {
                        largest = input.substr(mid - i, i + i + offset + 1);
                    }
                } else {
                    break;
                }
            }
        }
    }

    cout << largest;


}

Test 1

Verdict: TIME LIMIT EXCEEDED

Test 2

Verdict: TIME LIMIT EXCEEDED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: TIME LIMIT EXCEEDED

Test 6

Verdict: TIME LIMIT EXCEEDED

Test 7

Verdict: TIME LIMIT EXCEEDED