LeetCode-in-Rust
55. Jump Game
Medium
You are given an integer array nums. You are initially positioned at the array’s first index, and each element in the array represents your maximum jump length at that position.
Return true if you can reach the last index, or false otherwise.
Example 1:
Input: nums = [2,3,1,1,4]
Output: true
Explanation: Jump 1 step from index 0 to 1, then 3 steps to the last index.
Example 2:
Input: nums = [3,2,1,0,4]
Output: false
Explanation: You will always arrive at index 3 no matter what. Its maximum jump length is 0, which makes it impossible to reach the last index.
Constraints:
1 <= nums.length <= 1040 <= nums[i] <= 105
Solution
impl Solution {
pub fn can_jump(nums: Vec<i32>) -> bool {
let sz = nums.len();
let mut tmp = 1;
for i in 0..sz {
tmp -= 1;
if tmp < 0 {
return false;
}
// Update `tmp` to be the maximum value between current `tmp` and `nums[i]`.
tmp = tmp.max(nums[i]);
// Early exit: if `i + tmp` can reach or exceed the last index, return true.
if i + tmp as usize >= sz - 1 {
return true;
}
}
true
}
}