[LintCode] 跳跃游戏II Jump Game II

给出一个非负整数数组，你最初定位在数组的第一个位置。

数组中的每个元素代表你在那个位置可以跳跃的最大长度。　　　

你的目标是使用最少的跳跃次数到达数组的最后一个位置。

样例

给出数组A = [2,3,1,1,4]，最少到达数组最后一个位置的跳跃次数是2(从数组下标0跳一步到数组下标1，然后跳3步到数组的最后一个位置，一共跳跃2次)

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.

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.)

public class Solution {
/**
* @param A: A list of lists of integers
* @return: An integer
*/
public int jump(int[] A) {
if(null == A || A.length <= 1) return 0;
int max = 0, i = 0;
int count = 0;
while(max < A.length - 1) {
if(i+A[i] > max) {
max = i+A[i];
count++;
}
i++;
}
return count;
}
}