Problem:
Score : 200 points

Problem Statement

We have held a popularity poll for N items on sale. Item i received A_i votes.

From these N items, we will select M as popular items. However, we cannot select an item with less than \dfrac{1}{4M} of the total number of votes.

If M popular items can be selected, print Yes; otherwise, print No.

Constraints

1 \leq M \leq N \leq 100

1 \leq A_i \leq 1000

A_i are distinct.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M
A_1 ... A_N

Output

If M popular items can be selected, print Yes; otherwise, print No.

Sample Input 1

4 1
5 4 2 1

Sample Output 1

Yes

There were 12 votes in total. The most popular item received 5 votes, and we can select it.

Sample Input 2

3 2
380 19 1

Sample Output 2

No

There were 400 votes in total. The second and third most popular items received less than \dfrac{1}{4\times 2} of the total number of votes, so we cannot select them. Thus, we cannot select two popular items.

Sample Input 3

12 3
4 56 78 901 2 345 67 890 123 45 6 789

Sample Output 3

Yes

Solution in C (GCC 9.2.1) (judge verdict: Accepted)

#include<stdio.h>
int main(void)
{
  int N,M;
  int A[1000]={0};
  scanf("%d %d",&N,&M);
  int i;
  double sum=0;
  for(i=0;i<N;i++){
    scanf("%d",&A[i]);
    sum+=A[i];    
  }
  int num=0,flag=0;
  double n;
  n=sum/(4*M);
  for(i=0;i<N;i++){
  	if(A[i]>=n){
      num++;
      if(num>=M){
        flag=1;
      }
  	}
  }
  if(flag==1)
    printf("Yes");
  else
    printf("No");
  return 0;
}