README.md

45. Jump Game II

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].

Solutions (Rust)

1. Solution

impl Solution {
    pub fn jump(nums: Vec<i32>) -> i32 {
        let mut i = 0;
        let mut j = 0;
        let mut ret = 0;

        for k in 0..nums.len() {
            if k > i {
                i = j;
                ret += 1;
            }
            j = j.max(k + nums[k] as usize);
        }

        ret
    }
}