Find next greater element in array or find next greater element to right.
Given an input array, find the next greater element for every element of an array. The next greater element x is the first greater element on the right side of x in an array.
For example:
Example 1:
Input: {4, 2, 6, 8, 1, 0}
Output: {6, 6, 8, -1, -1, -1}
4 => 6 (The first next greater element of 4 is 6)
2 => 6 (Next greater element of 2 is 6)
6 => 8 (Next greater element of 6 is 8)
8 => -1 (No next greater element found)
1 => -1 (No next greater element found)
0 => -1
Example 2:
Input: {7, 8, 1, 4}
Output: {8, -1, 4, -1}