CodeForces - 1007A Reorder the Array (改版田忌赛马) | 贪心算法+STL排序

题目:

Reorder the Array

 CodeForces - 1007A 

You are given an array of integers. Vasya can permute (change order) its integers. He wants to do it so that as many as possible integers will become on a place where a smaller integer used to stand. Help Vasya find the maximal number of such integers.

For instance, if we are given an array [10,20,30,40][10,20,30,40], we can permute it so that it becomes [20,40,10,30][20,40,10,30]. Then on the first and the second positions the integers became larger (20>1020>10, 40>2040>20) and did not on the third and the fourth, so for this permutation, the number that Vasya wants to maximize equals 22. Read the note for the first example, there is one more demonstrative test case.

Help Vasya to permute integers in such way that the number of positions in a new array, where integers are greater than in the original one, is maximal.

Input

The first line contains a single integer nn (1≤n≤1051≤n≤105) — the length of the array.

The second line contains nn integers a1,a2,…,ana1,a2,…,an (1≤ai≤1091≤ai≤109) — the elements of the array.

Output

Print a single integer — the maximal number of the array's elements which after a permutation will stand on the position where a smaller element stood in the initial array.

Examples

Input

7
10 1 1 1 5 5 3

Output

4

Input

5
1 1 1 1 1

Output

0

Note

In the first sample, one of the best permutations is [1,5,5,3,10,1,1][1,5,5,3,10,1,1]. On the positions from second to fifth the elements became larger, so the answer for this permutation is 4.

In the second sample, there is no way to increase any element with a permutation, so the answer is 0.


题意:

  给你一个序列,你可以生成这个序列的任意一个排列,对于某个排列,如果这个排列上某个位置的值大于原序列的值,那么就会产生1的贡献,问你最大能有多少贡献。新版田忌赛马!自己的马和自己的马比赛,最多赢几场。


思路:

  先进行排序,然数列呈从小到大分布,用 sort 。之后利用贪心思想,从大到小逐个判定。


题解:

#include <bits/stdc++.h> 
using namespace std;
int main() {
	int a; 
   scanf("%d",&a);
   int j=a-2,k=0;
   int b[a];
   int i=0; 
   for(;i<a;i++){
   scanf("%d",&b[i]);
   }
   sort(b,b+a);
   i--;
   for(;j>=0;){
   		if(b[i]>b[j]){
   			i--;j--;k++;
		   }else{
		   	j--;
		   }
   	
   }
   printf("%d\n",k);
    return 0;
}

 

全部评论

相关推荐

自从我室友在计算机导论课上听说了“刷&nbsp;LeetCode&nbsp;是进入大厂的敲门砖”,整个人就跟走火入魔了一样。他在宿舍门口贴了一张A4纸,上面写着:“正在&nbsp;DP,请勿打扰,否则&nbsp;Time&nbsp;Limit&nbsp;Exceeded。”日记本的扉页被他用黑色水笔加粗描了三遍:“Talk&nbsp;is&nbsp;cheap.&nbsp;Show&nbsp;me&nbsp;the&nbsp;code。”连宿舍聚餐,他都要给我们讲解:“今天的座位安排可以用回溯算法解决,但为了避免栈溢出,我建议用动态规划。来,这是状态转移方程:dp[i][j]&nbsp;代表第&nbsp;i&nbsp;个人坐在第&nbsp;j&nbsp;个位置的最优解。”我让他去楼下取个快递,他不直接去,非要在门口踱步,嘴里念念有词:“这是一个图的遍历问题。从宿舍楼(root)到驿站(target&nbsp;node),我应该用&nbsp;BFS&nbsp;还是&nbsp;DFS?嗯,求最短路径,还是广度优先好。”和同学约好出去开黑,他会提前发消息:“集合点&nbsp;(x,&nbsp;y),我们俩的路径有&nbsp;k&nbsp;个交点,为了最小化时间复杂度,应该在&nbsp;(x/2,&nbsp;y/2)&nbsp;处汇合。”有一次另一个室友低血糖犯了,让他帮忙找颗糖,他居然冷静地分析道:“别急,这是一个查找问题。零食箱是无序数组,暴力查找是&nbsp;O(n)。如果按甜度排序,我就可以用二分查找,时间复杂度降到&nbsp;O(log&nbsp;n)。”他做卫生也要讲究算法效率:“拖地是典型的岛屿问题,要先把连通的污渍区块都清理掉。倒垃圾可以用双指针法,一个指针从左往右,一个从右往左,能最快匹配垃圾分类。”现在我们宿舍的画风已经完全变了,大家不聊游戏和妹子,对话都是这样的:“你&nbsp;Two&nbsp;Sum&nbsp;刷了几遍了?”“别提了,昨天遇到一道&nbsp;Hard&nbsp;题,我连暴力解都想不出来,最后只能看题解。你呢?”“我动态规划还不行,总是找不到最优子结构。今天那道接雨水给我整麻了。”……LeetCode&nbsp;真的害了我室友!!!
老六f:编程嘉豪来了
AI时代还有必要刷lee...
点赞 评论 收藏
分享
评论
点赞
收藏
分享

创作者周榜

更多
牛客网
牛客网在线编程
牛客网题解
牛客企业服务