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extern crate petgraph;
extern crate rand;
use petgraph::unionfind::UnionFind;
use rand::{thread_rng, ChaChaRng, Rng, SeedableRng};
use std::collections::HashSet;
#[test]
fn uf_test() {
let n = 8;
let mut u = UnionFind::new(n);
for i in 0..n {
assert_eq!(u.find(i), i);
assert_eq!(u.find_mut(i), i);
assert!(!u.union(i, i));
}
u.union(0, 1);
assert_eq!(u.find(0), u.find(1));
u.union(1, 3);
u.union(1, 4);
u.union(4, 7);
assert_eq!(u.find(0), u.find(3));
assert_eq!(u.find(1), u.find(3));
assert!(u.find(0) != u.find(2));
assert_eq!(u.find(7), u.find(0));
u.union(5, 6);
assert_eq!(u.find(6), u.find(5));
assert!(u.find(6) != u.find(7));
// check that there are now 3 disjoint sets
let set = (0..n).map(|i| u.find(i)).collect::<HashSet<_>>();
assert_eq!(set.len(), 3);
}
#[test]
fn uf_test_with_equiv() {
let n = 8;
let mut u = UnionFind::new(n);
for i in 0..n {
assert_eq!(u.find(i), i);
assert_eq!(u.find_mut(i), i);
assert!(u.equiv(i, i));
}
u.union(0, 1);
assert!(u.equiv(0, 1));
u.union(1, 3);
u.union(1, 4);
u.union(4, 7);
assert!(u.equiv(0, 7));
assert!(u.equiv(1, 3));
assert!(!u.equiv(0, 2));
assert!(u.equiv(7, 0));
u.union(5, 6);
assert!(u.equiv(6, 5));
assert!(!u.equiv(6, 7));
// check that there are now 3 disjoint sets
let set = (0..n).map(|i| u.find(i)).collect::<HashSet<_>>();
assert_eq!(set.len(), 3);
}
#[test]
fn uf_rand() {
let n = 1 << 14;
let mut rng = ChaChaRng::from_rng(thread_rng()).unwrap();
let mut u = UnionFind::new(n);
for _ in 0..100 {
let a = rng.gen_range(0, n);
let b = rng.gen_range(0, n);
let ar = u.find(a);
let br = u.find(b);
assert_eq!(ar != br, u.union(a, b));
}
}
#[test]
fn uf_u8() {
let n = 256;
let mut rng = ChaChaRng::from_rng(thread_rng()).unwrap();
let mut u = UnionFind::<u8>::new(n);
for _ in 0..(n * 8) {
let a = rng.gen();
let b = rng.gen();
let ar = u.find(a);
let br = u.find(b);
assert_eq!(ar != br, u.union(a, b));
}
}
#[test]
fn labeling() {
let mut u = UnionFind::<u32>::new(48);
for i in 0..24 {
u.union(i + 1, i);
}
for i in 25..47 {
u.union(i, i + 1);
}
u.union(23, 25);
u.union(24, 23);
let v = u.into_labeling();
assert!(v.iter().all(|x| *x == v[0]));
}
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