Jump Game
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# LeetCode #55: Jump Game (C/C++).

medium

source: https://leetcode.com/problems/jump-game/
C/C++ Solution to LeetCode problem 55. Jump Game.

## Problem

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.

## Examples

### 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

• 1 <= nums.length <= 104
• 0 <= nums[i] <= 105

## Solution

This problem is solved by using a greedy algorithm.

• For every position we calculate what is the maximun position we can reach.
• If the current position is beyond the max position we can reach, return false.
• If the maximum position is equal or greater than the last index, then return true.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 class Solution { public: bool canJump(vector<int>& nums) { int maxPosition = 0; for (int i=0; i<nums.size(); i++) { if (i > maxPosition) break; maxPosition = max(maxPosition, i + nums[i]); if (maxPosition >= (nums.size()-1)) return true; } return false; } };