Is Jump Game easy or hard?

Jump Game is rated Medium because the dynamic programming idea is straightforward but recognizing the greedy optimization is less obvious. Many candidates initially attempt DP before discovering that tracking the farthest reachable index solves the problem more efficiently.

Jump Game Python/Java solution

Most implementations use the greedy strategy. Iterate through the array and track the farthest reachable index using max(farthest, i + nums[i]). This logic translates directly to Python, Java, C++, JavaScript, and other languages with identical O(n) time complexity.

How to solve Jump Game in O(n)?

Traverse the array while maintaining a variable called farthest that stores the maximum reachable index so far. For each index i, verify that i is within the reachable range and update farthest = max(farthest, i + nums[i]). If farthest reaches or passes the last index, the result is true.

What is the best approach for Jump Game?

The greedy approach is considered the best solution. It tracks the farthest index reachable while iterating through the array. If the current index ever exceeds the farthest reachable position, the end cannot be reached. This solution runs in O(n) time with O(1) extra space.

Is Jump Game asked at Google/Amazon/Meta?

Jump Game is a common interview problem at large tech companies including Google, Amazon, and Meta. It tests greedy reasoning, array traversal, and the ability to reduce a dynamic programming formulation into an optimal linear-time solution.

What data structure is used in Jump Game?

The problem primarily uses arrays since the input is an integer array of jump lengths. The greedy solution only maintains a few integer variables, while the dynamic programming approach may use an additional boolean array to track reachable positions.

What is the time complexity of Jump Game?

The optimal greedy solution runs in O(n) time because the array is scanned once while maintaining the farthest reachable index. A dynamic programming approach can take O(n^2) time since it may check multiple jump possibilities for each index.

Description Solution Video 16:28

55. Jump Game

Medium41.2% acceptance33 companies

You are given an integer array nums. 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.

Example 1:

Input: nums = [2,3,1,1,4]
Output: true
Explanation: Jump 1 step from index 0 to 1, then 3 steps to the last index.

Example 2:

Input: nums = [3,2,1,0,4]
Output: false
Explanation: You will always arrive at index 3 no matter what. Its maximum jump length is 0, which makes it impossible to reach the last index.

Constraints: