[Greedy]45. Jump Game II

• 分类：Greedy
• 时间复杂度: O(n)

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.

Example:

Input: [2,3,1,1,4]
Output: 2
Explanation: 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.

代码：

方法:

class Solution:
    def jump(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        length=len(nums)
        distance=0
        biggest_step=0
        count=0
        
        for i in range(length):
            distance=max(distance,i+nums[i])
            if biggest_step!=length-1 and i==biggest_step:
                count+=1
                biggest_step=distance
                
        return count

讨论：

1.挺简单的贪心算法题= 。=
2.注意biggest_step!=length-1,已经到达终点了就不要count+1了