Compilare: user.cpp: In function ‘int main()’: user.cpp:50:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < nodes[subset].size(); ++ i) ^ user.cpp:17:17: warning: unused variable ‘ans’ [-Wunused-variable] int subset, ans, s, n, m, subsub, i, j, x, y, indepSet; ^ user.cpp:15:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colorare.in", "r", stdin); ^ user.cpp:16:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colorare.out", "w", stdout); ^ user.cpp:19:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:21:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^