Boxes Packing

Boxes Packing

Mishka has got n empty boxes. For every i (1 ≤ i ≤ n), i-th box is a

cube with side length ai.

Mishka can put a box i into another box j if the following conditions

are met:

i-th box is not put into another box; j-th box doesn’t contain any

other boxes; box i is smaller than box j (ai < aj). Mishka can put

boxes into each other an arbitrary number of times. He wants to

minimize the number of visible boxes. A box is called visible iff it

is not put into some another box.

Help Mishka to determine the minimum possible number of visible boxes!

Input The first line contains one integer n (1 ≤ n ≤ 5000) — the

number of boxes Mishka has got.

The second line contains n integers a1, a2, …, an (1 ≤ ai ≤ 109),

where ai is the side length of i-th box.

Output Print the minimum possible number of visible boxes.

Examples
Input
3
1 2 3
Output
1
Input
4
4 2 4 3
Output
2

Note In the first example it is possible to put box 1 into box 2, and

2 into 3.

In the second example Mishka can put box 2 into box 3, and box 4 into

box 1.

思路如下

• 题意：n个盒子，大盒子可以套到小盒子外边（前提是大盒子里面不能 有其它盒子），问当大盒子套小盒子，之后最后还剩下几个盒子能被看到
• 思路：在 n 个 盒子的边长中找出现次数最多的边长，该边长就是答案

题解如下

#include<iostream>
#include<algorithm>
using namespace std;

int main()
{
    int n;
    scanf("%d",&n);
    int ar[n + 5];

    for(int i = 0; i < n; i ++)
        scanf("%d", &ar[i]);

    sort(ar, ar + n);
    int i,j;
    int res = -1;
    for(i = n - 1; i >=0 ; i --)		//找出那条边出现现次数最多
    {
        int ans = 1;
        for(j = i - 1; j >= 0; j --)
        {
            if(ar[i] == ar[j])
                ans ++;
            else
            {
                i = j + 1;
                break;
            }
        }
        res = max(res , ans);
    }
    printf("%d",res);

    return 0;
}