README.md

962. Maximum Width Ramp

Given an array A of integers, a ramp is a tuple (i, j) for which i < j and A[i] <= A[j]. The width of such a ramp is j - i.

Find the maximum width of a ramp in A. If one doesn't exist, return 0.

Example 1:

Input: [6,0,8,2,1,5]
Output: 4
Explanation:
The maximum width ramp is achieved at (i, j) = (1, 5): A[1] = 0 and A[5] = 5.

Example 2:

Input: [9,8,1,0,1,9,4,0,4,1]
Output: 7
Explanation:
The maximum width ramp is achieved at (i, j) = (2, 9): A[2] = 1 and A[9] = 1.

Note:

1. 2 <= A.length <= 50000
2. 0 <= A[i] <= 50000

Solutions (Rust)

1. Sort

impl Solution {
    pub fn max_width_ramp(a: Vec<i32>) -> i32 {
        let mut v = a
            .iter()
            .enumerate()
            .map(|(i, n)| (n, i))
            .collect::<Vec<_>>();
        let mut min_i = a.len();
        let mut ret = 0;

        v.sort_unstable();

        for (_, i) in v {
            ret = ret.max(i.saturating_sub(min_i));
            min_i = min_i.min(i);
        }

        ret as i32
    }
}