LeetCode-in-Java

1033. Moving Stones Until Consecutive

Medium

There are three stones in different positions on the X-axis. You are given three integers a, b, and c, the positions of the stones.

In one move, you pick up a stone at an endpoint (i.e., either the lowest or highest position stone), and move it to an unoccupied position between those endpoints. Formally, let’s say the stones are currently at positions x, y, and z with x < y < z. You pick up the stone at either position x or position z, and move that stone to an integer position k, with x < k < z and k != y.

The game ends when you cannot make any more moves (i.e., the stones are in three consecutive positions).

Return an integer array answer of length 2 where:

Example 1:

Input: a = 1, b = 2, c = 5

Output: [1,2]

Explanation: Move the stone from 5 to 3, or move the stone from 5 to 4 to 3.

Example 2:

Input: a = 4, b = 3, c = 2

Output: [0,0]

Explanation: We cannot make any moves.

Example 3:

Input: a = 3, b = 5, c = 1

Output: [1,2]

Explanation: Move the stone from 1 to 4; or move the stone from 1 to 2 to 4.

Constraints:

Solution

import java.util.Arrays;

public class Solution {
    private int minMoves(int x, int y, int z) {
        if (x + 1 == y && y + 1 == z) {
            return 0;
        }
        if (y - x <= 2 || z - y <= 2) {
            return 1;
        }
        return 2;
    }

    private int maxMoves(int x, int z) {
        return z - x - 2;
    }

    public int[] numMovesStones(int a, int b, int c) {
        int[] t = {a, b, c};
        Arrays.sort(t);
        int min = minMoves(t[0], t[1], t[2]);
        int max = maxMoves(t[0], t[2]);
        return new int[] {min, max};
    }
}