Codeforce 296A - Yaroslav and Permutations

Yaroslav has an array that consists of n integers. In one second Yaroslav can swap two neighboring array elements. Now Yaroslav is wondering if he can obtain an array where any two neighboring elements would be distinct in a finite time.

Help Yaroslav.

Input

The first line contains integer n (1 ≤ n ≤ 100) — the number of elements in the array. The second line contains n integers a1, a2, ..., an(1 ≤ ai ≤ 1000) — the array elements.

Output

In the single line print "YES" (without the quotes) if Yaroslav can obtain the array he needs, and "NO" (without the quotes) otherwise.

Examples
input
1
1
output
YES
input
3
1 1 2
output
YES
input
4
7 7 7 7
output
NO
Note

In the first sample the initial array fits well.

In the second sample Yaroslav can get array: 1, 2, 1. He can swap the last and the second last elements to obtain it.

In the third sample Yarosav can't get the array he needs.

 题解:统计出现次数最多的 如果大于一半 就不满足

 1 #include <iostream>
 2 #include <algorithm>
 3 #include <cstring>
 4 #include <cstdio>
 5 #include <vector>
 6 #include <cstdlib>
 7 #include <iomanip>
 8 #include <cmath>
 9 #include <ctime>
10 #include <map>
11 #include <set>
12 using namespace std;
13 #define lowbit(x) (x&(-x))
14 #define max(x,y) (x>y?x:y)
15 #define min(x,y) (x<y?x:y)
16 #define MAX 100000000000000000
17 #define MOD 1000000007
18 #define pi acos(-1.0)
19 #define ei exp(1)
20 #define PI 3.141592653589793238462
21 #define INF 0x3f3f3f3f3f
22 #define mem(a) (memset(a,0,sizeof(a)))
23 typedef long long ll;
24 ll gcd(ll a,ll b){
25     return b?gcd(b,a%b):a;
26 }
27 const int N=105;
28 const int mod=1e9+7;
29 bool flag=0;
30 int a[N];
31 int main()
32 {
33     std::ios::sync_with_stdio(false);
34     int n,t;
35     cin>>n;
36     for(int i=0;i<n;i++){
37         cin>>t;
38         a[t]++;
39         if(a[t]>(n+1)/2) flag=1;
40     }
41     if(flag) cout<<"NO"<<endl;
42     else cout<<"YES"<<endl;
43     return 0;
44 }
posted @ 2017-07-31 17:20  wydxry  阅读(277)  评论(0编辑  收藏  举报
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