/in/foo.cc: In function 'int main()':
/in/foo.cc:5:6: warning: unused variable 'price' [-Wunused-variable]
  int price,demand,number,min_price,c,able,cost=0;
      ^
/in/foo.cc:5:36: warning: unused variable 'c' [-Wunused-variable]
  int price,demand,number,min_price,c,able,cost=0;
                                    ^
/in/foo.cc:8:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&demand,&number);
                                ^
/in/foo.cc:12:43: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d%d",&arr[i-1][0],&arr[i-1][1]);
                                           ^
/in/foo.cc:37:25: warning: '_min' may be used uninitialized in this function [-Wmaybe-uninitialized]
           arr[_min][1]=0;
                         ^
/in/foo.cc:35:21: warning: 'able' may be used uninitialized in this function [-Wmaybe-uninitialized]
        demand=demand-able;
                     ^