Compilare: user.cpp: In function ‘int main()’: user.cpp:45:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<a[x].size(); ++i) ^ user.cpp:26:36: warning: unused variable ‘xa’ [-Wunused-variable] int st,dr,x,y,i,n,m,x1,y1,dist,xa; ^ user.cpp:24:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sate.in","r",stdin); ^ user.cpp:25:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sate.out","w",stdout); ^ user.cpp:27:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&n,&m,&x1,&y1); ^ user.cpp:30:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&x,&y,&dist); ^