zoukankan      html  css  js  c++  java
  • Codeforces Round #466 (Div. 2) A. Points on the line[数轴上有n个点,问最少去掉多少个点才能使剩下的点的最大距离为不超过k。]

    A. Points on the line
    time limit per test
    1 second
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    We've got no test cases. A big olympiad is coming up. But the problemsetters' number one priority should be adding another problem to the round.

    The diameter of a multiset of points on the line is the largest distance between two points from this set. For example, the diameter of the multiset {1, 3, 2, 1} is 2.

    Diameter of multiset consisting of one point is 0.

    You are given n points on the line. What is the minimum number of points you have to remove, so that the diameter of the multiset of the remaining points will not exceed d?

    Input

    The first line contains two integers n and d (1 ≤ n ≤ 100, 0 ≤ d ≤ 100) — the amount of points and the maximum allowed diameter respectively.

    The second line contains n space separated integers (1 ≤ xi ≤ 100) — the coordinates of the points.

    Output

    Output a single integer — the minimum number of points you have to remove.

    Examples
    Input
    Copy
    3 1
    2 1 4
    Output
    1
    Input
    Copy
    3 0
    7 7 7
    Output
    0
    Input
    Copy
    6 3
    1 3 4 6 9 10
    Output
    3
    Note

    In the first test case the optimal strategy is to remove the point with coordinate 4. The remaining points will have coordinates 1 and 2, so the diameter will be equal to 2 - 1 = 1.

    In the second test case the diameter is equal to 0, so its is unnecessary to remove any points.

    In the third test case the optimal strategy is to remove points with coordinates 1, 9 and 10. The remaining points will have coordinates 3, 4 and 6, so the diameter will be equal to 6 - 3 = 3.

    [题意]:数轴上有n个点,最少去掉多少个点才能使剩下的点的最大距离为不超过k

    [分析]:排序后选的一定是段连续的区间,枚举左右端点即可.排序后n^2枚举区间。一般求合法个数的在区间上做文章.

    先排序。元素较少,直接暴力枚举每一个元素num[i],left=i-1记录该元素左边的数目,然后找第一个大于等于num[i]+d的元素num[j],用right=n-j记录下该元素右边的数目。找到最小的(left+right)就是要删除的数目。

    [代码]:

    /*
    题意:给两个数n和d,然后输入n个数,问最少要删掉几个数才能让剩下的n个数的任意两个数相差不大于d
    */
    #include<bits/stdc++.h>
    using namespace std;
    #define pb push_back
    #define mem(a) memset(a,0,sizeof(a))
    typedef long long ll;
    typedef pair<int,int> pii;
    const int maxn=150;
    const int inf=0x3f3f3f3f;
    int main()
    {
        int n,d,a[maxn],ans=1e9;
        cin>>n>>d;
        for(int i=1;i<=n;i++)
            cin>>a[i];
        sort(a+1,a+n+1);
        for(int i=1;i<=n;i++)
        {
            for(int j=i;j<=n;j++)
            {
                if(a[j]-a[i]<=d) ans=min(ans,i-1+n-j);//满足条件:序列中最小值和最大值相差<=d
            }
        }
        cout<<ans<<endl;
    }
    双重枚举
  • 相关阅读:
    lombok 下的@Builder注解用法
    (springboot)自定义Starter
    各种 Spring-Boot-Starters系列 介绍
    MQ的使用场景
    SpringBoot中使用rabbitmq,activemq消息队列和rest服务的调用
    RPC原理详解
    Java性能优化的50个细节
    thinkphp3.2.2有预览的多图上传
    关于php中的exec命令
    关于thinkphp3.1无法加载模块解决办法
  • 原文地址:https://www.cnblogs.com/Roni-i/p/8470787.html
Copyright © 2011-2022 走看看