zoukankan      html  css  js  c++  java
  • codeforces 877C

    C. Slava and tanks
    time limit per test2 seconds
    memory limit per test256 megabytes
    inputstandard input
    outputstandard output
    Slava plays his favorite game "Peace Lightning". Now he is flying a bomber on a very specific map.

    Formally, map is a checkered field of size 1 × n, the cells of which are numbered from 1 to n, in each cell there can be one or several tanks. Slava doesn't know the number of tanks and their positions, because he flies very high, but he can drop a bomb in any cell. All tanks in this cell will be damaged.

    If a tank takes damage for the first time, it instantly moves to one of the neighboring cells (a tank in the cell n can only move to the cell n - 1, a tank in the cell 1 can only move to the cell 2). If a tank takes damage for the second time, it's counted as destroyed and never moves again. The tanks move only when they are damaged for the first time, they do not move by themselves.

    Help Slava to destroy all tanks using as few bombs as possible.

    Input
    The first line contains a single integer n (2 ≤ n ≤ 100 000) — the size of the map.

    Output
    In the first line print m — the minimum number of bombs Slava needs to destroy all tanks.

    In the second line print m integers k1, k2, ..., km. The number ki means that the i-th bomb should be dropped at the cell ki.

    If there are multiple answers, you can print any of them.

    Examples
    input
    2
    output
    3
    2 1 2
    input
    3
    output
    4
    2 1 3 2

    (这一题。。能想到会感觉太容易了,像我这种想不到的。。就会不知道从哪入手。。。

    解题思路:先炸偶数,这样坦克都会跑到奇数,再炸奇数,奇数上的坦克都会跑到偶数,再炸偶数,就全炸死了。

    ac代码:

     1 #include <iostream>
     2 #include <cstdio>
     3 using namespace std;
     4 int main() {
     5     int n;
     6     scanf("%d",&n);
     7     printf("%d
    ",n+n/2);
     8     for(int i=2;i<=n;i+=2) {
     9         printf("%d ",i);
    10     }
    11    // printf("
    ");
    12     for(int i=1;i<=n;i+=2) {
    13         printf("%d ",i);
    14     }
    15   //  printf("
    ");
    16     for(int i=2;i<=n;i+=2) {
    17         printf("%d ",i);
    18     }
    19  //   printf("
    ");
    20     return 0;
    21 }
    View Code
  • 相关阅读:
    想想学习C已经有9年了, 应该可以写一些东西了.——转
    python gmail 多个收件人
    翻译_工具建议
    C语言的可变参数——转
    XP专业版中安装了IIS,配置好之后只能访问静态htm网页,图片之类的,但是ASP 文件确不能读取,提示无法显示网页提示
    ubuntu 修改IP,网关等
    java发送邮件
    在MyEclipse中配置Tomcat服务器
    国外程序员推荐:每个程序员都应读的书(转载)
    100个有关管理的网站
  • 原文地址:https://www.cnblogs.com/zmin/p/7725142.html
Copyright © 2011-2022 走看看