zoukankan      html  css  js  c++  java
  • Codeforces 849D.Rooter's Song

    D. Rooter's Song
    time limit per test
    2 seconds
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    Wherever the destination is, whoever we meet, let's render this song together.

    On a Cartesian coordinate plane lies a rectangular stage of size w × h, represented by a rectangle with corners (0, 0), (w, 0), (w, h) and (0, h). It can be seen that no collisions will happen before one enters the stage.

    On the sides of the stage stand n dancers. The i-th of them falls into one of the following groups:

    • Vertical: stands at (xi, 0), moves in positive y direction (upwards);
    • Horizontal: stands at (0, yi), moves in positive x direction (rightwards).

    According to choreography, the i-th dancer should stand still for the first ti milliseconds, and then start moving in the specified direction at 1 unit per millisecond, until another border is reached. It is guaranteed that no two dancers have the same group, position and waiting time at the same time.

    When two dancers collide (i.e. are on the same point at some time when both of them are moving), they immediately exchange their moving directions and go on.

    Dancers stop when a border of the stage is reached. Find out every dancer's stopping position.

    Input

    The first line of input contains three space-separated positive integers n, w and h (1 ≤ n ≤ 100 000, 2 ≤ w, h ≤ 100 000) — the number of dancers and the width and height of the stage, respectively.

    The following n lines each describes a dancer: the i-th among them contains three space-separated integers gi, pi, and ti (1 ≤ gi ≤ 2, 1 ≤ pi ≤ 99 999, 0 ≤ ti ≤ 100 000), describing a dancer's group gi (gi = 1 — vertical, gi = 2 — horizontal), position, and waiting time. If gi = 1 then pi = xi; otherwise pi = yi. It's guaranteed that 1 ≤ xi ≤ w - 1 and 1 ≤ yi ≤ h - 1. It is guaranteed that no two dancers have the same group, position and waiting time at the same time.

    Output

    Output n lines, the i-th of which contains two space-separated integers (xi, yi) — the stopping position of the i-th dancer in the input.

    Examples
    Input
    8 10 8
    1 1 10
    1 4 13
    1 7 1
    1 8 2
    2 2 0
    2 5 14
    2 6 0
    2 6 1
    Output
    4 8
    10 5
    8 8
    10 6
    10 2
    1 8
    7 8
    10 6
    Input
    3 2 3
    1 1 2
    2 1 1
    1 1 5
    Output
    1 3
    2 1
    1 3
    Note

    The first example corresponds to the initial setup in the legend, and the tracks of dancers are marked with different colours in the following figure.

    In the second example, no dancers collide.

    【题解】

    不(题)难(解)发(上)现(说)两个点能够相碰当且仅当p - t相等

    于是我们可以按照p - t分组,发现两个点相碰可以看做穿过去。那么

    最终位置与原始位置有什么对应关系呢?

    我们把每个点的路径化成直线,交点意味着碰撞。我们发现一个点的行走轨迹是

    阶梯状的,手画一下不难发现:左上->左下->右下方向的点对应左上->右上->

    右下的点

    于是两次间接排序即可

     1 #include <iostream>
     2 #include <cstdio>
     3 #include <cstdlib>
     4 #include <cstring>
     5 #include <algorithm>
     6 #define max(a, b) ((a) > (b) ? (a) : (b))
     7 #define min(a, b) ((a) < (b) ? (a) : (b))
     8 
     9 const int INF = 0x3f3f3f3f;
    10 const int MAXN = 1000000 + 10;
    11 
    12 inline void read(int &x)
    13 {
    14     x = 0;char ch = getchar(), c = ch;
    15     while(ch < '0' || ch > '9')c = ch, ch = getchar();
    16     while(ch <= '9' && ch >= '0')x = x * 10 + ch - '0', ch = getchar();
    17     if(c == '-')x = -x;
    18 }
    19 
    20 inline int abs(int a)
    21 {
    22     return a < 0 ? -1*a : a;
    23 } 
    24 
    25 struct Node
    26 {
    27     int g, p, t, x, y;
    28 }node[MAXN],ans[MAXN];
    29 
    30 int n,w,h,cnt[MAXN],cnt2[MAXN];
    31 
    32 int cmp(int c, int d)
    33 {
    34     Node a = node[c], b = node[d];
    35     return (a.p - a.t == b.p - b.t) ? ( (a.y == b.y) ? (a.x > b.x) : (a.y < b.y)) : (a.p - a.t < b.p - b.t);
    36 }
    37 
    38 int cmp2(int c, int d)
    39 {
    40     Node a = node[c], b = node[d];
    41     return (a.p - a.t == b.p - b.t) ? ((a.x == b.x) ? (a.y < b.y) : (a.x > b.x)) : (a.p - a.t < b.p - b.t);
    42 }
    43 
    44 int main()
    45 {
    46     read(n), read(w), read(h);
    47     for(register int i = 1;i <= n;++ i)
    48     {
    49         read(node[i].g), read(node[i].p), read(node[i].t);
    50         if(node[i].g == 1) node[i].y = -1, node[i].x = node[i].p;
    51         else node[i].y = node[i].p, node[i].x = -1;
    52         cnt[i] = cnt2[i] = i;
    53     }
    54     std::sort(cnt + 1, cnt + 1 + n, cmp);
    55     for(register int i = 1;i <= n;++ i)
    56         if(node[i].x != -1)node[i].y = h;
    57         else node[i].x = w;
    58     std::sort(cnt2 + 1, cnt2 + 1 + n, cmp2);
    59     for(register int i = 1;i <= n;++ i)
    60         ans[cnt[i]] = node[cnt2[i]];
    61     for(register int i = 1;i <= n;++ i)
    62         printf("%d %d
    ", ans[i].x, ans[i].y);
    63     return 0;
    64 }
    849D
  • 相关阅读:
    Centeos7搭建selenium+Chrome浏览器
    数据结构学习篇之栈和队列
    数据结构学习篇之线性表
    Tornado基础学习篇
    Python控制函数运行时间
    python线程实现异步任务
    Python实现几种简单的排序算法
    python爬虫遇到会话存储sessionStorage
    Python 有哪些优雅的代码实现让自己的代码更pythonic?
    Ubuntu查看端口使用情况,使用netstat命令:
  • 原文地址:https://www.cnblogs.com/huibixiaoxing/p/7649108.html
Copyright © 2011-2022 走看看