A799.Falling Portals--Platinum

省选/NOI-

USACO

通过率:0%

时间限制:1.00s

内存限制:128MB

题目描述

There are NN (2N21052\le N\le 2\cdot 10^5) worlds, each with a portal. Initially,
world ii (for 1iN1 \leq i \leq N) is at xx-coordinate ii, and yy-coordinate
AiA_i (1Ai1091\le A_i\le 10^9). There is also a cow on each world. At time 00,
all yy-coordinates are distinct and the worlds start falling: world ii moves
continuously in the negative-yy direction at a speed of ii units per second.
At any time when two worlds are at the same yy-coordinate (possibly a
fractional time), the portals "align", meaning that a cow on one of the worlds
can choose to travel instantaneously to the other world.
For each ii, the cow on world ii wants to travel to world QiQ_i (QiiQ_i\neq i). Help each cow determine how long her journey will take, if she travels
optimally.
Each query output should be a fraction a/ba/b where aa and bb are positive
and relatively prime integers, or 1-1 if it the journey is impossible.

输入格式

  • Test cases 2-3 satisfy N100.N\le 100.
  • Test cases 4-5 satisfy N2000.N\le 2000.
  • Test cases 6-14 satisfy no additional constraints.

输出格式

The first line of input contains a single integer N.N.
The next line contains NN space-separated integers A1,A2,,AN.A_1,A_2,\ldots,A_N.
The next line contains NN space-separated integers Q1,Q2,,QN.Q_1,Q_2,\ldots,Q_N.
Print NN lines, the ii-th of which contains the journey length for cow i.i.

输入输出样例

  • 输入#1

    4
    3 5 10 2
    3 3 2 1

    输出#1

    7/2
    7/2
    5/1
    -1
    

说明/提示

Consider the answer for the cow originally on world 2. At time 22 worlds 1
and 2 align, so the cow can travel to world 1. At time 72\frac{7}{2} worlds 1
and 3 align, so the cow can travel to world 3.

首页