Compilare: user.cpp: In function ‘void solve_tree()’: user.cpp:54:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < must.size(); i++) ^ user.cpp:55:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i + 1; j < must.size(); j++) ^ user.cpp: In function ‘void backTracking(int, int)’: user.cpp:69:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pas == use.size()) { ^ user.cpp: In function ‘int main()’: user.cpp:87:29: warning: too many arguments for format [-Wformat-extra-args] scanf("%d%d", &n, &m, &k); ^ user.cpp:84:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("subarbore.in","r",stdin); ^ user.cpp:85:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("subarbore.out","w",stdout); ^ user.cpp:87:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m, &k); ^ user.cpp:94:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&cost); ^ user.cpp:103:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:105:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^