JumpGame2.java

/*
You are given a 0-indexed array of integers nums of length n. You are initially positioned at nums[0].
Each element nums[i] represents the maximum length of a forward jump from index i. In other words, if you are at nums[i], you can jump to any nums[i + j] where:
0 <= j <= nums[i] and
i + j < n
Return the minimum number of jumps to reach nums[n - 1]. The test cases are generated such that you can reach nums[n - 1].
Example 1:
Input: nums = [2,3,1,1,4]
Output: 2
Explanation: The minimum number of jumps to reach the last index is 2. Jump 1 step from index 0 to 1, then 3 steps to the last index.
Example 2:
Input: nums = [2,3,0,1,4]
Output: 2
*/ 
class Solution {
    // [2 3 1 1 4] ------> blue - 2 , green----> [3 1], purple -----> [1 4] dont consider jump with
    // in prev wnd
    public int jump(int[] nums) {
        int left = 0, right = 0;
        int res = 0;

        while(right < nums.length-1){
            int farthest = 0;
            for(int i = left;i <= right;i++){
                farthest = Math.max(farthest, i + nums[i]);
            }
            left = right + 1;
            right = farthest;
            res++;
        }

        return res;
    }
}