palindrome.cpp: In function 'int main()':
palindrome.cpp:12:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < S.size(); i++) {
~~^~~~~~~~~~
palindrome.cpp:13:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int j = i; j < S.size(); j++) {
~~^~~~~~~~~~
palindrome.cpp:18:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < S.size(); i++) {
~~^~~~~~~~~~
palindrome.cpp:25:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < S.size(); i++) {
~~^~~~~~~~~~
palindrome.cpp:26:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int j = i; j < S.size(); j++) {
~~^~~~~~~~~~