LeetCode 896. Monotonic Array

Problem Statement

impl Solution {
    pub fn is_monotonic(a: Vec<i32>) -> bool {
        if a.len() == 1 {
            return true;
        }
        
        let mut flag = 0;
        for i in 1..a.len() {
            if a[i - 1] == a[i] {
                continue;
            }
            let mut cur = 0;
            if a[i - 1] < a[i] {
                cur = 1;
            } else {
                cur = 2;
            }
            if flag != 0 && flag != cur {
                return false;
            }
            flag = cur;
        }
        return true;
    }
}