C :

#include<stdio.h>
#include<string.h>
#include<math.h>
int num2[1010];
int max(int a)
{
	int result;
	result=num2[0];
	for(int i=0;i<a;i++)
	{
		if(num2[i]>result)
		result=num2[i];
	}
	return result;
}
main()
{
	int num1[1010],count;
	float n;
	while(scanf("%f",&n)!=EOF)
	{
		memset(num2,0,sizeof(int)*1010);
		for(int i=0;i<n;i++)
		{
			scanf("%d",&num1[i]);
			int count=0;
			for(int j=0;j<i;j++)
			if(num1[j]==num1[i])
			count++;
			num2[i]=count+1;
		}
		if(max(1010)<=ceil(n/2))
		puts("YES");
		else
		puts("NO");
	}
}

C++ :

#include <cstdio> 
#include <cstring> 
#include <algorithm> 
using namespace std; 
const int V = 1000 + 50; 
int n, sum[V]; 
int main() { 
    int i, j; 
    while(~scanf("%d", &n)) { 
        memset(sum, 0, sizeof(sum)); 
        for(i = 0; i < n; ++i) { 
            int temp; 
            scanf("%d", &temp); 
            sum[temp]++; 
        } 
        int Max = 0; 
        for(i = 1; i <= 1000; ++i) 
            Max = max(Max, sum[i]); 
        if(Max <= (n + 1) / 2) 
            printf("YES\n"); 
        else
            printf("NO\n"); 
    } 
}