foo.cc: In function 'int main()':
foo.cc:42:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &V, &M, &n);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
foo.cc:47:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%d", &v[i], &m[i], &c[i]);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。