Compilare: user.cpp: In function ‘bool solve(std::string)’: user.cpp:10:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < s.size(); ++ i) ^ user.cpp:14:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(cnt == 0 || cnt == s.size()) ^ user.cpp:17:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(cnt <= s.size() / 2) ^ user.cpp:18:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < s.size(); ++ i) ^ user.cpp:24:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < s.size() - 1; ++ i) ^ user.cpp:32:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < s.size() && s[i] == 'A') ^ user.cpp:39:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < s.size()) { ^ user.cpp:52:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < s.size() && s[i] == 'A') { ^ user.cpp:64:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < s.size() && s[i] == 'A') ^ user.cpp:68:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < s.size()) { ^ user.cpp:81:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < s.size() && s[i] == 'A') { ^ user.cpp: In function ‘int main()’: user.cpp:92:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("csir.in", "r", stdin); ^ user.cpp:93:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("csir.out", "w", stdout); ^