ICP Nearest Neighbor Step

Problem

Run one nearest-neighbor step of iterative closest point.

For each source point return the index of the closest target point in 3D Euclidean distance, breaking ties toward the smallest index. Return one index per source point.

Hint

Squared distance gives the same ordering as distance, so skip the square root.

Test cases

case 1

in: [[[0,0,0],[5,5,5]],[[1,0,0],[0,1,0],[4,4,4]]]

expected: [0,2]

case 2

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

expected: [0]

case 3

in: [[[3,0,0],[0,3,0]],[[3,0,0],[0,3,0],[3,3,3]]]

expected: [0,1]

case 4

in: [[[0,0,0],[10,10,10]],[[-1,-1,-1]]]

expected: [0,0]

Starter codePython

def icp_nearest(source, target):
    # Your code here
    pass

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