Google Online Assessment 2021 (OA) - Rings on Rods
You have 10 rods numbered from 0 to 9. There are three types of rings, red, green and blue, being put on the rods. You get a point for each rod that has a ring of each color on it, i.e. to get a point you need a red ring, green ring and blue ring on one rod.
A ring put on a rod is represented by two characters, the first describes the color of the ring and the second describes which number rod it is on from 0 to 9. For example "R8" means that a red ring is being put on the 8th rod.
s: a corrent string of length 2N describing the N rings put on rods
how many points you will get
1s = B2R5G2R2
One point for rings put on the second rod.