Compilare: user.cpp: In function ‘int main()’: user.cpp:9:88: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("coach.in","r",stdin),freopen("coach.out","w",stdout),scanf("%d%d%d",&n,&m,&t); ^ user.cpp:9:88: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] user.cpp:9:88: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] user.cpp:11:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i].x),a[i].y=i; ^ user.cpp:13:50: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&i,&j,&k),b[i][j]=b[j][i]=k; ^