Compilare: user.cpp: In function ‘void solve()’: user.cpp:129:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < V[x].size(); ++ j) ^ user.cpp: In function ‘void read()’: user.cpp:103:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trilant.in", "r", stdin); ^ user.cpp:104:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:105:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &a[0], &a[1], &a[2]); ^ user.cpp:108:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &z); ^ user.cpp: In function ‘void write()’: user.cpp:157:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trilant.out", "w", stdout); ^