LeetCode 45 Jump Game II

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.)

Note:

You can assume that you can always reach the last index.

贪心法：

public int jump(int[] nums) {
int reach = 0;//最右能跳到哪里
int last = 0;//上次落的的最大号阶梯,如果当前超过了,那必然是step了一下
int step = 0;//步数
for (int i = 0; i < nums.length; i++) {
if (i > last) {
step++;
last = reach;
}
reach = Math.max(reach, i + nums[i]);
}
return step;
}