leetcode_rust/
remove_duplicates_2.rs

1#![allow(dead_code)]
2
3pub fn remove_duplicates(nums: &mut Vec<i32>) -> i32 {
4    if nums.len() <= 2 {
5        return nums.len() as i32;
6    }
7    let mut count = 0;
8    let mut twice = false;
9    for i in 0..nums.len() - 1 {
10        if nums[i] != nums[i + 1] {
11            twice = false;
12            count += 1;
13            nums[count] = nums[i + 1];
14        // twice
15        } else if nums[i] == nums[i + 1] && !twice {
16            twice = true;
17            count += 1;
18            nums[count] = nums[i + 1];
19        }
20    }
21    count as i32 + 1
22}
23
24pub fn remove_duplicates2(nums: &mut Vec<i32>) -> i32 {
25    if nums.len() <= 2 {
26        return nums.len() as i32;
27    }
28
29    let mut i = 1;
30    let mut k = i - 1;
31    let mut j = i + 1;
32
33    while j < nums.len() {
34        if (nums[j] != nums[i]) || (nums[j] == nums[i] && nums[j] != nums[k]) {
35            k += 1;
36            nums[i + 1] = nums[j];
37            i += 1;
38        }
39        j += 1;
40    }
41
42    (i + 1) as i32
43}
44
45// use incremental nature
46pub fn remove_duplicates3(nums: &mut Vec<i32>) -> i32 {
47    let mut i = 0;
48    for j in 0..nums.len() {
49        if j < 2 || nums[j] > nums[i - 2] {
50            nums[i] = nums[j];
51            i += 1;
52        }
53    }
54    i as i32
55}
56
57#[cfg(test)]
58mod tests {
59    use super::*;
60
61    #[test]
62    fn test1() {
63        let mut nums = vec![1, 1, 1, 2, 2, 3];
64        assert_eq!(remove_duplicates(&mut nums), 5);
65
66        let mut nums = vec![0, 0, 1, 1, 1, 1, 2, 3, 3];
67        assert_eq!(remove_duplicates(&mut nums), 7);
68
69        let mut nums = vec![1, 1, 1, 2, 2, 3];
70        assert_eq!(remove_duplicates(&mut nums), 5);
71    }
72
73    #[test]
74    fn test2() {
75        let mut nums = vec![1, 1, 1, 2, 2, 3];
76        assert_eq!(remove_duplicates2(&mut nums), 5);
77
78        let mut nums = vec![0, 0, 1, 1, 1, 1, 2, 3, 3];
79        assert_eq!(remove_duplicates2(&mut nums), 7);
80
81        let mut nums = vec![1, 1, 1, 2, 2, 3];
82        assert_eq!(remove_duplicates2(&mut nums), 5);
83    }
84
85    #[test]
86    fn test3() {
87        let mut nums = vec![1, 1, 1, 2, 2, 3];
88        assert_eq!(remove_duplicates3(&mut nums), 5);
89
90        let mut nums = vec![0, 0, 1, 1, 1, 1, 2, 3, 3];
91        assert_eq!(remove_duplicates3(&mut nums), 7);
92
93        let mut nums = vec![1, 1, 1, 2, 2, 3];
94        assert_eq!(remove_duplicates3(&mut nums), 5);
95    }
96}
leetcode_rust/remove_duplicates_2.rs

leetcode_rust/
remove_duplicates_2.rs
