755. Pour Water

// LeetCode URL: https://leetcode.com/problems/pour-water/

/**
 * Just follow the rules defined in the problem.
 *
 * Time Complexity: O(V * N)
 *
 * Space Complexity: O(1).
 *
 * If we want to save the original array, then we will create a copy of original
 * array and modify the new array with the resultant heights. Space Complexity
 * will still be O(1).
 *
 * N = Length of the heights array.
 */
class Solution {
    public int[] pourWater(int[] heights, int V, int K) {
        if (heights == null) {
            return new int[0];
        }

        int len = heights.length;
        if (len == 0 || K < 0 || V == 0 || K >= len) {
            return heights;
        }

        while (V > 0) {
            int index = K;
            for (int i = K - 1; i >= 0; i--) {
                if (heights[i] > heights[index]) {
                    break;
                }
                if (heights[i] < heights[index]) {
                    index = i;
                }
            }

            if (index != K) {
                heights[index]++;
                V--;
                continue;
            }

            for (int i = K + 1; i < len; i++) {
                if (heights[i] > heights[index]) {
                    break;
                }
                if (heights[i] < heights[index]) {
                    index = i;
                }
            }
            heights[index]++;
            V--;
        }

        return heights;
    }
}