Jump game v

Array Dynamic Programming Sorting

64.8% acceptance

Feb 25, 2026

1187

Given an array of integers arr and an integer d. In one step you can jump from index i to index: i + x where: i + x < arr.length and 0 < x <= d. i - x where: i - x >= 0 and 0 < x <= d. In addition, you can only jump from index i to index j if arr[i] > arr[j] and arr[i] > arr[k] for all indices k between i and j (More formally min(i, j) < k < max(i, j)). You can choose any index of the array and start jumping. Return the maximum number of indices you can visit. Notice that you can not jump outside of the array at any time.

Solution

Rust

Time O(n)

Space O(n)

LeetCode

solution.rs

impl Solution {
  pub fn max_jumps(arr: Vec<i32>, d: i32) -> i32 {
    let n = arr.len();
    let d = d as usize;
    let mut dp = vec![0i32; n];

    fn dfs(i: usize, arr: &[i32], d: usize, dp: &mut Vec<i32>) -> i32 {
      if dp[i] > 0 { return dp[i]; }
      let n = arr.len();
      let mut best = 1;
      // Jump right
      for j in 1..=d {
        if i + j >= n || arr[i + j] >= arr[i] { break; }
        best = best.max(1 + dfs(i + j, arr, d, dp));
      }
      // Jump left
      for j in 1..=d {
        if j > i || arr[i - j] >= arr[i] { break; }
        best = best.max(1 + dfs(i - j, arr, d, dp));
      }
      dp[i] = best;
      best
    }

    (0..n).map(|i| dfs(i, &arr, d, &mut dp)).max().unwrap_or(0)
  }
}