Compilare: user.cpp: In function ‘int search(int)’: user.cpp:26:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(step=1;step<l.size()-1;step<<=1); ^ user.cpp:28:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i+step<l.size() && a[l[i+step]].y<val) ^ user.cpp: In function ‘void read()’: user.cpp:15:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:16:65: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1;i<=n;i++) scanf("%d%d",&a[i].x,&a[i].y),a[i].y--; ^ user.cpp: In function ‘int main()’: user.cpp:64:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("intfm.in","r",stdin); ^ user.cpp:65:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("intfm.out","w",stdout); ^