CF1714F.Build a Tree and That Is It

普及/提高-

通过率:0%

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题目描述

A tree is a connected undirected graph without cycles. Note that in this problem, we are talking about not rooted trees.

You are given four positive integers n,d12,d23n, d_{12}, d_{23} and d31d_{31} . Construct a tree such that:

  • it contains nn vertices numbered from 11 to nn ,
  • the distance (length of the shortest path) from vertex 11 to vertex 22 is d12d_{12} ,
  • distance from vertex 22 to vertex 33 is d23d_{23} ,
  • the distance from vertex 33 to vertex 11 is d31d_{31} .

Output any tree that satisfies all the requirements above, or determine that no such tree exists.

输入格式

The first line of the input contains an integer tt ( 1t1041 \le t \le 10^4 ) —the number of test cases in the test.

This is followed by tt test cases, each written on a separate line.

Each test case consists of four positive integers n,d12,d23n, d_{12}, d_{23} and d31d_{31} ( 3n2105;1d12,d23,d31n13 \le n \le 2\cdot10^5; 1 \le d_{12}, d_{23}, d_{31} \le n-1 ).

It is guaranteed that the sum of nn values for all test cases does not exceed 21052\cdot10^5 .

输出格式

For each test case, print YES if the suitable tree exists, and NO otherwise.

If the answer is positive, print another n1n-1 line each containing a description of an edge of the tree — a pair of positive integers xi,yix_i, y_i , which means that the ii th edge connects vertices xix_i and yiy_i .

The edges and vertices of the edges can be printed in any order. If there are several suitable trees, output any of them.

输入输出样例

  • 输入#1

    9
    5 1 2 1
    5 2 2 2
    5 2 2 3
    5 2 2 4
    5 3 2 3
    4 2 1 1
    4 3 1 1
    4 1 2 3
    7 1 4 1

    输出#1

    YES
    1 2
    4 1
    3 1
    2 5
    YES
    4 3
    2 5
    1 5
    5 3
    NO
    YES
    2 4
    4 1
    2 5
    5 3
    YES
    5 4
    4 1
    2 5
    3 5
    YES
    2 3
    3 4
    1 3
    NO
    YES
    4 3
    1 2
    2 4
    NO
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