Jump Game II (Java)

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.

Your goal is to reach the last index in the minimum number of jumps.

For example:
Given array A = [2,3,1,1,4]

The minimum number of jumps to reach the last index is 2. (Jump 1 step from index 0 to 1, then 3 steps to the last index.)

比Jump Game多加一個計數flag，但凡i走過了一個當前min的時候flag+1，然後將目前統計的最大max賦值給min。

Source

public class Solution {
    public int jump(int[] A) {
        if(A.length == 0)
        	return 0;
        int max = 0;
        int min = 0;
        int flag = 0;
        
        for(int i = 0; i < A.length && i <= max; i++){
        	if(i > min){
        		flag++;
        		min = max;
        	}
        	
        	if(max < A[i] + i){
        		max = A[i] + i;
        	}
        }
        if(max >= A.length - 1){
        	return flag;
        }
        else return 0;
    }
}

Test

    public static void main(String[] args){
    	int[] A = {5, 9, 3, 2, 1, 0, 2, 3, 3, 1, 0, 0}; 
    	
    	System.out.println(new Solution().jump(A));
    }