LC: 1182. Shortest Distance to Target Color

https://leetcode.com/problems/shortest-distance-to-target-color/

Question

1182. Shortest Distance to Target Color

You are given an array colors, in which there are three colors: 1, 2 and 3.

You are also given some queries. Each query consists of two integers i and c, return the shortest distance between the given index i and the target color c. If there is no solution return -1.

Example 1:

Input: colors = [1,1,2,1,3,2,2,3,3], queries = [[1,3],[2,2],[6,1]]
Output: [3,0,3]
Explanation: 
The nearest 3 from index 1 is at index 4 (3 steps away).
The nearest 2 from index 2 is at index 2 itself (0 steps away).
The nearest 1 from index 6 is at index 3 (3 steps away).

Example 2:

Input: colors = [1,2], queries = [[0,3]]
Output: [-1]
Explanation: There is no 3 in the array.

Constraints:

• 1 <= colors.length <= 5*10^4

• 1 <= colors[i] <= 3

• 1 <= queries.length <= 5*10^4

• queries[i].length == 2

• 0 <= queries[i][0] < colors.length

• 1 <= queries[i][1] <= 3

The Essence

Details and Solutions