Jump Game | Problems

You are initially positioned at the array's first index, and each element in the array represents your maximum jump length at that position. Return true if you can reach the last index, or false otherwise.

Sample Input

nums = [2,3,1,1,4]

Sample Output

true

Constraints

1 <= nums.length <= 10^4
0 <= nums[i] <= 10^5

Test Cases

Case 1

Args: [[2,3,1,1,4]] Expected: true

Topics

Array Two Pointers

Iterate through the array while maintaining the farthest index you can reach. If you ever land on an index beyond your current reach, return false. Otherwise, update your reach as max(maxReach, i + nums[i]).

function canJump(nums) {
  let maxReach = 0;

  for (let i = 0; i < nums.length; i++) {
    if (i > maxReach) return false;
    maxReach = Math.max(maxReach, i + nums[i]);
  }

  return true;
}

Time: O(n) Space: O(1)

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