CF1205D.Almost All

普及/提高-

通过率:0%

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题目描述

You are given a tree with nn nodes. You have to write non-negative integers on its edges so that the following condition would be satisfied:

For every two nodes ii , jj , look at the path between them and count the sum of numbers on the edges of this path. Write all obtained sums on the blackboard. Then every integer from 11 to 2n29\lfloor \frac{2n^2}{9} \rfloor has to be written on the blackboard at least once.

It is guaranteed that such an arrangement exists.

输入格式

The first line contains a single integer nn ( 1n10001 \le n \le 1000 ) — the number of nodes.

Each of the next n1n-1 lines contains two integers uu and vv ( 1u,vn1 \le u, v \le n , uvu \neq v ), meaning that there is an edge between nodes uu and vv . It is guaranteed that these edges form a tree.

输出格式

Output n1n-1 lines, each of form uu vv xx ( 0x1060 \le x \le 10^6 ), which will mean that you wrote number xx on the edge between uu , vv .

Set of edges (u,v)(u, v) has to coincide with the set of edges of the input graph, but you can output edges in any order. You can also output ends of edges in an order different from the order in input.

输入输出样例

  • 输入#1

    3
    2 3
    2 1
    

    输出#1

    3 2 1
    1 2 2
    
  • 输入#2

    4
    2 4
    2 3
    2 1
    

    输出#2

    4 2 1
    3 2 2
    1 2 3
    
  • 输入#3

    5
    1 2
    1 3
    1 4
    2 5
    

    输出#3

    2 1 1
    5 2 1
    3 1 3
    4 1 6
    

说明/提示

In the first example, distance between nodes 11 and 22 is equal to 22 , between nodes 22 and 33 to 11 , between 11 and 33 to 33 .

In the third example, numbers from 11 to 99 (inclusive) will be written on the blackboard, while we need just from 11 to 55 to pass the test.

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