1306. Jump Game III

Given an array of non-negative integers `arr`, you are initially positioned at `start` index of the array. When you are at index `i`, you can jump to `i + arr[i]` or `i - arr[i]`, check if you can reach to any index with value 0.

Notice that you can not jump outside of the array at any time.

Example 1:

```Input: arr = [4,2,3,0,3,1,2], start = 5
Output: true
Explanation:
All possible ways to reach at index 3 with value 0 are:
index 5 -> index 4 -> index 1 -> index 3
index 5 -> index 6 -> index 4 -> index 1 -> index 3
```

Example 2:

```Input: arr = [4,2,3,0,3,1,2], start = 0
Output: true
Explanation:
One possible way to reach at index 3 with value 0 is:
index 0 -> index 4 -> index 1 -> index 3
```

Example 3:

```Input: arr = [3,0,2,1,2], start = 2
Output: false
Explanation: There is no way to reach at index 1 with value 0.
```

Constraints:

• `1 <= arr.length <= 5 * 104`
• `0 <= arr[i] < arr.length`
• `0 <= start < arr.length`

1306. Jump Game III
``````struct Solution;
use std::collections::VecDeque;

impl Solution {
fn can_reach(arr: Vec<i32>, start: i32) -> bool {
let n = arr.len();
let mut visited = vec![false; n];
let mut queue = VecDeque::new();
queue.push_back(start);
visited[start as usize] = true;
while let Some(i) = queue.pop_front() {
if arr[i as usize] == 0 {
return true;
} else {
let l = i - arr[i as usize];
let r = i + arr[i as usize];
if l >= 0 && !visited[l as usize] {
visited[l as usize] = true;
queue.push_back(l);
}
if r < n as i32 && !visited[r as usize] {
visited[r as usize] = true;
queue.push_back(r);
}
}
}
false
}
}

#[test]
fn test() {
let arr = vec![4, 2, 3, 0, 3, 1, 2];
let start = 5;
let res = true;
assert_eq!(Solution::can_reach(arr, start), res);
let arr = vec![4, 2, 3, 0, 3, 1, 2];
let start = 0;
let res = true;
assert_eq!(Solution::can_reach(arr, start), res);
let arr = vec![3, 0, 2, 1, 2];
let start = 2;
let res = false;
assert_eq!(Solution::can_reach(arr, start), res);
}
``````