Problem_55. Jump Game - xwu36/LeetCode GitHub Wiki

Problem:

Given an array of non-negative integers, you are initially positioned at the first index of the array.

Each element in the array represents your maximum jump length at that position.

Determine if you are able to reach the last index.

For example:
A = [2,3,1,1,4], return true.

A = [3,2,1,0,4], return false.

Algorithm:

Greedy:
Consider all the previous steps which reach current index, and pick the greatest one.

Code:

class Solution {
    public boolean canJump(int[] nums) {
        if(nums == null || nums.length == 0)
            return false;
        int n = nums.length;
        if(n == 1) return true;
        int pre = 0;
        for(int i = 0; i < n; i++){
            nums[i] = Math.max(pre - 1, nums[i]);
            if(nums[i] <= 0 && i != n - 1) return false;
            pre = nums[i];
        }
        return true;
    }
}