76 lines
1.9 KiB
Rust
76 lines
1.9 KiB
Rust
struct PositionPermut {
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max_length: usize,
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number_of_digits: usize,
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idx: usize,
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total_number_of_iterations: usize,
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}
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impl Iterator for PositionPermut {
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type Item = Vec<i64>;
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fn next(&mut self) -> Option<Self::Item> {
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if self.idx == (self.total_number_of_iterations) {
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return None;
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};
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let pos1 = self.idx % self.number_of_digits;
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let pos0 = 0;
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let x = vec![pos0 as i64, pos1 as i64];
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let result = Some(x);
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self.idx += 1;
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result
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}
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}
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impl PositionPermut {
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fn new(max_length: usize) -> Self {
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assert!(max_length >= 3);
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let total_number_of_iterations = (1..max_length + 1).sum();
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Self {
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max_length,
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number_of_digits: 2,
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idx: 0,
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total_number_of_iterations,
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}
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}
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fn test(&mut self) {
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// length_of_numbers = 4
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// number_of_digits = 2
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[0, 1];
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[0, 2];
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[0, 3];
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[1, 2];
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[1, 3];
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[2, 3];
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// number_of_digits = 3
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[0, 1, 2];
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[0, 1, 3];
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[0, 2, 3];
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[1, 2, 3];
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}
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}
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#[cfg(test)]
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mod test {
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#[test]
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fn test_permutation() {
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use crate::permutation::PositionPermut;
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use std::collections::HashSet;
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let permutator = PositionPermut::new(3);
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let result: HashSet<_> = permutator.into_iter().collect();
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let mut solution = HashSet::new();
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solution.insert(vec![0, 1]);
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solution.insert(vec![0, 2]);
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solution.insert(vec![0, 3]);
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solution.insert(vec![1, 2]);
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solution.insert(vec![1, 3]);
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solution.insert(vec![2, 3]);
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// solution.insert(vec![0, 1, 2]);
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// solution.insert(vec![0, 1, 3]);
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// solution.insert(vec![0, 2, 3]);
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// solution.insert(vec![1, 2, 3]);
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// assert_eq!(result.len(), solution.len());
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assert_eq!(result, solution);
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}
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}
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