CF1387A.Graph

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题目描述

You are given an undirected graph where each edge has one of two colors: black or red.

Your task is to assign a real number to each node so that:

  • for each black edge the sum of values at its endpoints is 11 ;
  • for each red edge the sum of values at its endpoints is 22 ;
  • the sum of the absolute values of all assigned numbers is the smallest possible.

Otherwise, if it is not possible, report that there is no feasible assignment of the numbers.

输入格式

The first line contains two integers NN ( 1N1000001 \leq N \leq 100\,000 ) and MM ( 0M2000000 \leq M \leq 200\,000 ): the number of nodes and the number of edges, respectively. The nodes are numbered by consecutive integers: 1,2,,N1, 2, \ldots, N .

The next MM lines describe the edges. Each line contains three integers aa , bb and cc denoting that there is an edge between nodes aa and bb ( 1a,bN1 \leq a, b \leq N ) with color cc ( 11 denotes black, 22 denotes red).

输出格式

If there is a solution, the first line should contain the word "YES" and the second line should contain NN space-separated numbers. For each ii ( 1iN1 \le i \le N ), the ii -th number should be the number assigned to the node ii .

Output should be such that:

  • the sum of the numbers at the endpoints of each edge differs from the precise value by less than 10610^{-6} ;
  • the sum of the absolute values of all assigned numbers differs from the smallest possible by less than 10610^{-6} .

If there are several valid solutions, output any of them.

If there is no solution, the only line should contain the word "NO".

Scoring

Subtasks:

  1. (5 points) N5N \leq 5 , M14M \leq 14
  2. (12 points) N100N \leq 100
  3. (17 points) N1000N \leq 1000
  4. (24 points) N10000N \leq 10\,000
  5. (42 points) No further constraints

输入输出样例

  • 输入#1

    4 4
    1 2 1
    2 3 2
    1 3 2
    3 4 1

    输出#1

    YES
    0.5 0.5 1.5 -0.5
  • 输入#2

    2 1
    1 2 1

    输出#2

    YES
    0.3 0.7
  • 输入#3

    3 2
    1 2 2
    2 3 2

    输出#3

    YES
    0 2 0
  • 输入#4

    3 4
    1 2 2
    2 2 1
    2 1 1
    1 2 2

    输出#4

    NO

说明/提示

Note that in the second example the solution is not unique.

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