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 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>

int int_sort( const void * a , const void * b ) {
  /* 引数はvoid*型と規定されているのでint型にcastする */
  if( *( int * )a < *( int * )b ) {
    return -1;
  }
  else
  if( *( int * )a == *( int * )b ) {
    return 0;
  }
  return 1;
}

int main(void) {
  int n, m, i, sum=0;
  int* a;
  scanf("%d %d", &n, &m);
  a = (int*)malloc(sizeof(int)*n);
  for(i=0; i<n; i++) {
    scanf("%d", &a[i]);
    sum += a[i];
  }
  qsort((void*)a, n, sizeof(int), int_sort);
  if(a[n-m] < sum/(4*m)) {
    printf("No\n");
  }
  else {
    printf("Yes\n");
  }
  return 0;
}