Greedy Coloring by Degree

Problem

Color an undirected graph greedily in descending degree order.

Sort nodes by (-degree, index), then give each node the smallest non-negative color not used by an already colored neighbor. edges is a simple undirected [u, v] list. Return colors in node-index order.

Hint

High-degree nodes go first, which usually keeps the palette small.

Test cases

case 1

in: [3,[[0,1],[1,2]]]

expected: [1,0,1]

case 2

in: [4,[[0,1],[0,2],[0,3]]]

expected: [0,1,1,1]

case 3

in: [3,[[0,1],[1,2],[2,0]]]

expected: [0,1,2]

case 4

in: [3,[[0,1],[0,2]]]

expected: [0,1,1]

case 5

in: [4,[[0,1],[1,2],[2,0],[2,3]]]

expected: [1,2,0,1]

Starter codePython

def greedy_coloring_by_degree(n, edges):
    # Your code here
    pass

5 test cases · run your code against them in the editor