LeetCode_ 55_ Jumping game

Topic link

• https://leetcode.cn/problems/jump-game/

Title Description

Given an array of nonnegative integers nums , You're in the beginning of the array The first subscript .

Each element in the array represents the maximum length you can jump at that location .

Judge whether you can reach the last subscript .

Example 1：

 Input ：nums = [2,3,1,1,4]
 Output ：true
 explain ： You can jump first  1  Step , From the subscript  0  Reach subscript  1,  And then from the subscript  1  jump  3  Step to the last subscript .

Example 2：

 Input ：nums = [3,2,1,0,4]
 Output ：false
 explain ： No matter what , Always arrive, subscript  3  The location of . But the maximum jump length of the subscript is  0 ,  So it's never possible to reach the last subscript .

Tips ：

• 1 <= nums.length <= 3 * 10^4
• 0 <= nums[i] <= 10^5

Their thinking

The law of greed

• Take the maximum number of jump steps each time , Finally, if the total number of steps is greater than or equal to the length of the array , The explanation can

AC Code

class Solution {
    
    public boolean canJump(int[] nums) {
    
        int len = nums.length;
        int jumpStep = 0;
        if(len == 1){
    
            return true;
        }
        for (int i = 0; i <= jumpStep; i++) {
    
            jumpStep = Math.max(i + nums[i], jumpStep);
            if (jumpStep >= len - 1) {
    
                return true;
            }
        }
        return false;
    }
}