Intuition

Check if current index is further than reach

Approach

• Init reach to be 0 - Loop through nums

• Check if index>reach

• If so, return false - Update reach to be the max between (i+nums[i], reach) - Return true

Complexity

• Time complexity: O(n)

• Space complexity: O(1)

Code

    public boolean canJump(int[] nums) {
        int reach = 0;
        int n = nums.length;
        for (int i =0; i<n; i++){
            if (i>reach)
                return false;
            reach = Math.max(reach,i+nums[i]);
        }
        return true;
    }
}

class Solution:
    def canJump(self, nums: List[int]) -> bool:
        reach=0
        for i in range(len(nums)):
            if i>reach:
                return False
            reach=max(reach,i+nums[i])
        return True