/in/foo.cc: In function 'int main()':
/in/foo.cc:11:63: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[20]' [-Wformat=]
   scanf("%s %d %d %c %c %d",&s[i],&score1,&score2,&c1,&c2,&num);
                                                               ^
/in/foo.cc:7:43: warning: 'k' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int n,sum=0,maxn=0,score1,score2,num,a,b,k;
                                           ^