Compilare: user.cpp: In function ‘int main()’: user.cpp:68:15: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(wh[last].size()!=0) ^ user.cpp:93:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=1;j<wh[i].size();j++) { ^ user.cpp:50:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("psir.in","r",stdin); ^ user.cpp:51:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("psir.out","w",stdout); ^ user.cpp:53:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:54:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i=1;i<=n;i++) scanf("%d",&v[i]); ^