/in/foo.cc: In function 'int main()':
/in/foo.cc:12:18: error: too many arguments to function 'void sum(int*, int, int, int, int)'
  sum(c, k,n,1,0,0);
                  ^
/in/foo.cc:11:7: note: declared here
  void sum(int[], int, int, int, int);
       ^~~
/in/foo.cc:5:21: warning: unused variable 't' [-Wunused-variable]
  int n, k, c[20], i,t=0,s=0;
                     ^
/in/foo.cc:5:25: warning: unused variable 's' [-Wunused-variable]
  int n, k, c[20], i,t=0,s=0;
                         ^