foo.cc: In function 'void getab(long long int, int)':
foo.cc:39:12: warning: unused variable 'j' [-Wunused-variable]
     int i, j;
            ^
foo.cc: In function 'int main()':
foo.cc:53:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
foo.cc:54:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(i = 1; i <= n; i++) scanf("%d", &d[i].v);
                             ~~~~~^~~~~~~~~~~~~~~
foo.cc:73:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld%d", &x, &m);
     ~~~~~^~~~~~~~~~~~~~~~~~
foo.cc:83:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%lld", &j, &x);
         ~~~~~^~~~~~~~~~~~~~~~~~

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