sorting_vec/
lib.rs

1use std::collections::BTreeMap;
2
3pub fn btree_sort<T: Ord>(vec: Vec<T>) -> BTreeMap<T, usize> {
4    vec.into_iter().fold(BTreeMap::new(), |mut acc, e| {
5        let b = acc.entry(e).or_insert(0);
6        *b += 1;
7        acc
8    })
9}
10
11pub trait BTreeSort<T: Ord> {
12    fn uniques(self) -> Vec<T>;
13    fn sorted(self) -> Vec<T>;
14    fn reverse_uniques(self) -> Vec<T>;
15    fn reverse_sort(self) -> Vec<T>;
16}
17
18impl<T: Ord + Clone> BTreeSort<T> for BTreeMap<T, usize> {
19    fn uniques(self) -> Vec<T> {
20        self.into_iter().map(|(k, _)| k).collect::<Vec<T>>()
21    }
22
23    fn reverse_uniques(self) -> Vec<T> {
24        let mut ord = self.into_iter().map(|(k, _)| k).collect::<Vec<T>>();
25        ord.reverse();
26        ord
27    }
28
29    fn sorted(self) -> Vec<T> {
30        self.into_iter()
31            .map(|(k, v)| vec![k; v])
32            .flatten()
33            .collect::<Vec<T>>()
34    }
35
36    fn reverse_sort(self) -> Vec<T> {
37        let mut ord = self
38            .into_iter()
39            .map(|(k, v)| vec![k; v])
40            .flatten()
41            .collect::<Vec<T>>();
42        ord.reverse();
43        ord
44    }
45}
46
47impl<T: Ord + Clone> BTreeSort<T> for Vec<T> {
48    fn uniques(self) -> Vec<T> {
49        btree_sort(self).into_iter().map(|(k, _)| k).collect::<Vec<T>>()
50    }
51
52    fn reverse_uniques(self) -> Vec<T> {
53        let mut ord = btree_sort(self).into_iter().map(|(k, _)| k).collect::<Vec<T>>();
54        ord.reverse();
55        ord
56    }
57
58    fn sorted(self) -> Vec<T> {
59        btree_sort(self).into_iter()
60            .map(|(k, v)| vec![k; v])
61            .flatten()
62            .collect::<Vec<T>>()
63    }
64
65    fn reverse_sort(self) -> Vec<T> {
66        let mut ord = btree_sort(self)
67            .into_iter()
68            .map(|(k, v)| vec![k; v])
69            .flatten()
70            .collect::<Vec<T>>();
71        ord.reverse();
72        ord
73    }
74}
75
76#[cfg(test)]
77mod test {
78    use super::*;
79
80    #[test]
81    fn integers() {
82        let vec = vec![7, 3, 4, 5, 6, 8, 3, 2, -4, 5, 7, 8, 0, 9];
83        let sort = btree_sort(vec);
84
85        assert_eq!(sort.clone().uniques(), vec![-4, 0, 2, 3, 4, 5, 6, 7, 8, 9]);
86        assert_eq!(
87            sort.sorted(),
88            vec![-4, 0, 2, 3, 3, 4, 5, 5, 6, 7, 7, 8, 8, 9]
89        );
90    }
91
92    #[test]
93    fn usize() {
94        let vec: Vec<usize> = vec![7, 3, 4, 5, 6, 8, 3, 2, 5, 7, 8, 0, 9];
95        let sort = btree_sort(vec);
96
97        assert_eq!(sort.clone().uniques(), vec![0, 2, 3, 4, 5, 6, 7, 8, 9]);
98        assert_eq!(
99            sort.clone().sorted(),
100            vec![0, 2, 3, 3, 4, 5, 5, 6, 7, 7, 8, 8, 9]
101        );
102        assert_eq!(sort.reverse_uniques(), vec![9, 8, 7, 6, 5, 4, 3, 2, 0]);
103    }
104
105    #[test]
106    fn chars() {
107        let vec = vec!['h', 'g', 'p', 'a', 'c', 'g'];
108        let sort = btree_sort(vec);
109
110        assert_eq!(sort.clone().uniques(), vec!['a', 'c', 'g', 'h', 'p']);
111        assert_eq!(sort.clone().sorted(), vec!['a', 'c', 'g', 'g', 'h', 'p']);
112        assert_eq!(sort.reverse_sort(), vec!['p', 'h', 'g', 'g', 'c', 'a']);
113    }
114
115    #[test]
116    fn string() {
117        let vec = vec!["ha", "he", "ga", "12", "pow", "he", "543", "as", "cd", "ga"];
118        let sort = btree_sort(vec);
119
120        assert_eq!(
121            sort.clone().uniques(),
122            vec!["12", "543", "as", "cd", "ga", "ha", "he", "pow"]
123        );
124        assert_eq!(
125            sort.sorted(),
126            vec!["12", "543", "as", "cd", "ga", "ga", "ha", "he", "he", "pow"]
127        );
128    }
129
130    #[test]
131    fn vec_usize() {
132        let vec: Vec<usize> = vec![7, 3, 4, 5, 6, 8, 3, 2, 5, 7, 8, 0, 9];
133
134        assert_eq!(vec.clone().uniques(), vec![0, 2, 3, 4, 5, 6, 7, 8, 9]);
135        assert_eq!(
136            vec.clone().sorted(),
137            vec![0, 2, 3, 3, 4, 5, 5, 6, 7, 7, 8, 8, 9]
138        );
139        assert_eq!(vec.reverse_uniques(), vec![9, 8, 7, 6, 5, 4, 3, 2, 0]);
140    }
141}
sorting_vec/lib.rs

sorting_vec/
lib.rs
