LeetCode Medium Challenge Day 13 | Jump Game

QUESTION LINK - CLICK

Problem Statement:

You are given an array nums where nums[i] represents the maximum number of steps you can jump forward from that position. You need to determine if you can reach the last index starting from the first index.

Step-by-Step Explanation:

1. Initialization:

- goal is initialized to the last index of the array (`nums.length - 1`). This variable represents the position we want to reach.

2. Iterating Backwards through the Array:

- A for loop iterates from the last index to the first index (right to left).

- For each index i, the condition i + nums[i] >= goal is checked:

- This condition checks if you can jump from the current index i to or beyond the current goal.

3. Updating the Goal:

- If the condition i + nums[i] >= goal is true, it means you can jump from index i to or beyond the current goal. In this case, update goal to the current index i.

4. Checking the Result:

- After the loop completes, check if goal is 0. If goal is 0, it means you can reach the last index from the first index, and the function returns true.

- If goal is not 0, it means you cannot reach the last index, and the function returns false.

CODE

class Solution {
    public boolean canJump(int[] nums) {
        int goal = nums.length - 1;
        for (int i = goal; i >= 0; i--) {
            if (i + nums[i] >= goal) {
                goal = i;
            }
        }
        return goal == 0;
    }
}