Compilare: user.cpp: In function ‘int main()’: user.cpp:18:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i <= M; i ++){ ^ user.cpp:30:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i <= M; i ++) ^ user.cpp:14:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("triplete.in" ,"r", stdin ); ^ user.cpp:15:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("triplete.out","w", stdout); ^ user.cpp:17:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:19:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &X, &Y); ^