Compilare: user.cpp: In function ‘void extractheap()’: user.cpp:44:9: warning: unused variable ‘son’ [-Wunused-variable] int son; ^ user.cpp: In function ‘int main()’: user.cpp:78:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<v[i].size();j++) { ^ user.cpp:89:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<sol.size();i++) ^ user.cpp:54:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in","r",stdin); ^ user.cpp:55:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out","w",stdout); ^ user.cpp:56:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:60:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&x,&y,&z); ^