leetcode-45-Jump-Game-II

描述


Given an array of non-negative integers nums, 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.

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

Example 1:

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Input: nums = [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.

Example 2:

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Input: nums = [2,3,0,1,4]
Output: 2

Constraints:

  • 1 <= nums.length <= 104
  • 0 <= nums[i] <= 1000

分析


这题用的是贪心的做法。

解决方案1(Python)


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class Solution:
def jump(self, nums: List[int]) -> int:
numsLen = len(nums)
maxPos, end, step = 0, 0, 0

for i in range(numsLen-1):
if maxPos >= i:
maxPos = max(maxPos, i+nums[i])
if i == end:
end = maxPos
step += 1
return step

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