Compilare: user.cpp: In function ‘bool pairup(int)’: user.cpp:15:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[dad].size();i++){ ^ user.cpp:23:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[dad].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:34:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.in","r",stdin); ^ user.cpp:35:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.out","w",stdout); ^ user.cpp:36:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n1,&n2,&m); ^ user.cpp:39:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^