Jump Game II

Problem

You are given a 0-indexed array of integers nums of length n. You are initially positioned at nums[0].

Each element nums[i] represents the maximum length of a forward jump from index i. In other words, if you are at nums[i], you can jump to any nums[i + j] where:

• 0 <= j <= nums[i] and
• i + j < n

Return the minimum number of jumps to reach nums[n - 1]. The test cases are generated such that you can reach nums[n - 1].

 

Example 1:

**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:

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

 

Constraints:

• 1 <= nums.length <= 104
• 0 <= nums[i] <= 1000
• It's guaranteed that you can reach nums[n - 1].

Code

✅ Javascript

Solution

题目含义：

解题思路：

var jump = function (nums) {
    let ans = 0, jp = 0, far = 0
    for (let i = 0; i < nums.length - 1; i++) {
        jp = Math.max(jp, nums[i] + i)
        if (i === far) {
            far = jp
            ans++
        }
    }
    return ans
};

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