Compilare: user.cpp: In function ‘int down(int)’: user.cpp:37:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int up(int)’: user.cpp:47:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int add(int)’: user.cpp:54:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int del(int)’: user.cpp:60:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:83:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[nd].size();j++) ^ user.cpp:63:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cezar.in","r",stdin); ^ user.cpp:64:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cezar.out","w",stdout); ^ user.cpp:65:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ user.cpp:68:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^