Compilare: user.cpp: In function ‘void findGoodPairing(int)’: user.cpp:29:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < v[i].size(); j++) ^ user.cpp:40:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < v[i].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:128:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < v[i].size(); j++) ^ user.cpp:161:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (j < v[i].size()) ^ user.cpp:93:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ulei.in", "r", stdin); ^ user.cpp:94:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ulei.out", "w", stdout); ^ user.cpp:96:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); ^ user.cpp:100:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:112:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &i, &j, &cul); ^