GAZAR

Principal Engineer | Mentor

Jump Game II Algorithm

Jump Game II Algorithm

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].

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.

var jump = function(nums) {
    let maxReach = 0;
    let jumps = 0;
    let end = 0;
    for (let i = 0; i < nums.length - 1 ; i++) {        
        maxReach = Math.max(maxReach, i+nums[i])

        if (i === end) {
            jumps++
            end = maxReach
        }
    }
    return jumps;
};