/in/foo.cc: In function 'int main()':
/in/foo.cc:10:31: error: 'nC' was not declared in this scope
     for( int i = 1; i< sizeof(nC)/sizeof(int); i++)
                               ^~
/in/foo.cc:14:18: error: 'nVol' was not declared in this scope
             if(j<nVol[i])
                  ^~~~
/in/foo.cc:6:9: warning: unused variable 'nCo' [-Wunused-variable]
     int nCo[6] = {0 , 2 , 5 , 3 , 10 , 4};  //花费
         ^~~
/in/foo.cc:24:13: error: expected '}' at end of input
     return 0;
             ^