[LeetCode]#2103. Rings and Rods

Environment: Python 3.8

Key technique: set, if, for

There are n rings and each ring is either red, green, or blue. The rings are distributed across ten rods labeled from 0 to 9.

You are given a string rings of length 2n that describes the n rings that are placed onto the rods. Every two characters in rings forms a color-position pair that is used to describe each ring where:

  • The first character of the ith pair denotes the ith ring's color ('R', 'G', 'B').
  • The second character of the ith pair denotes the rod that the ith ring is placed on ('0' to '9').

For example, "R3G2B1" describes n == 3 rings: a red ring placed onto the rod labeled 3, a green ring placed onto the rod labeled 2, and a blue ring placed onto the rod labeled 1.

Return the number of rods that have all three colors of rings on them.

Example 1:

Analysis:

  1. Use set array
  2. Search each location rod its R, G, B rings as below.
  3. Return each set length =>3.

Solution:

Submissions:

Reference:

https://leetcode.com/problems/rings-and-rods/discuss/1624322/Python3-array-of-sets

--

--

Interesting in any computer science.

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store