foo.cc: In function 'int main()':
foo.cc:41:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&t);
    ~~~~~^~~~~~~~~
foo.cc:49:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d%d%d",&x[i],&y[i],&tof[i]);
             ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~