Compilare: main.cpp: In function 'int main()': main.cpp:119:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j0 = 0; j0 < s[0].size(); j0++) { ~~~^~~~~~~~~~~~~ main.cpp:120:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j1 = 0; j1 < s[1].size(); j1++) { ~~~^~~~~~~~~~~~~ main.cpp:130:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j0 = 0; j0 < s[0].size(); j0++) ~~~^~~~~~~~~~~~~ main.cpp:131:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j1 = 0; j1 < s[1].size(); j1++) ~~~^~~~~~~~~~~~~ main.cpp: In constructor 'InputReader::InputReader(const char*)': main.cpp:28:43: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^ main.cpp: In member function 'void InputReader::advance()': main.cpp:56:47: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^