jumpGame2.js

/*
45. Jump Game II

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
*/

/**
 * @param {number[]} nums
 * @return {number}
 */
var jump = function (nums) {
    let jumps = 0;
    let currentJumpEnd = 0;
    let farthest = 0;

    for (let i = 0; i < nums.length - 1; i++) {
        farthest = Math.max(farthest, i + nums[i]);
        if (i === currentJumpEnd) {
            jumps++;
            currentJumpEnd = farthest;
        }
    }
    return jumps;

};

console.log(jump([2, 3, 1, 1, 4]))
console.log(jump([2, 3, 0, 1, 4]))
console.log(jump([1, 1, 1, 1, 1]))