那是化简后的向上取整。。。

> #include <stdio.h>
> #include <memory.h>
> int child[100001];
> int n,d;
> 
> int get_child(int c){
>     int p,m,s=0;
>     while(c>d){
> 		s+=(p=c/d);
>         m=c%d;
> 		c=p+m;
> 	}
> 	return s;
> }
> 
> int main() {
>     int i, c, sum;
>     while(scanf("%d %d", &n, &d)!=EOF){
> 		sum=0;
> 	memset(child,0,sizeof(int)*(n+1));
>     for(i = 0; i < n; i++){
>         scanf("%d", &c);
>         child[c]++;
>     }
> 	
>     for(i = 0; i < n; i++)
>         if(child[i] > d)
> 			sum+=get_child(child[i]);
> 		printf("%d\n", sum);
> 	}
> 		return 1;
> }