Compilare: main.cpp: In function 'int main()': main.cpp:36:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<sol.size(); i++){ ~^~~~~~~~~~~ main.cpp:8:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] { freopen("perechi2.in", "r", stdin); ^ main.cpp:9:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("perechi2.out", "w", stdout); ^ main.cpp:11:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^