// FILE NOT TESTED

extern crate snarl;

use snarl::UnionFind;

#[test]
fn test_single() {
    let mut union_find = UnionFind::new(1);
    assert_eq!(union_find.components(), 1);
    assert_eq!(union_find.representative(0), 0);
    union_find.finalize();
    assert_eq!(union_find.components(), 1);
    assert_eq!(union_find.component(0), 0);
}

#[test]
fn test_separate_pair() {
    let mut union_find = UnionFind::new(2);
    assert_eq!(union_find.components(), 2);
    assert_eq!(union_find.representative(0), 0);
    assert_eq!(union_find.representative(1), 1);
    union_find.finalize();
    assert_eq!(union_find.components(), 2);
    assert_eq!(union_find.component(0), 0);
    assert_eq!(union_find.component(1), 1);
}

#[test]
fn test_merged_pair() {
    let mut union_find = UnionFind::new(2);
    assert_eq!(union_find.components(), 2);
    assert_eq!(union_find.representative(0), 0);
    assert_eq!(union_find.representative(1), 1);
    union_find.merge(1, 0);
    assert_eq!(union_find.components(), 1);
    assert_eq!(union_find.representative(0), 1);
    assert_eq!(union_find.representative(1), 1);
    union_find.finalize();
    assert_eq!(union_find.components(), 1);
    assert_eq!(union_find.component(0), 0);
    assert_eq!(union_find.component(1), 0);
}

#[test]
fn test_merged_many() {
    let elements = 8;
    let mut union_find = UnionFind::new(elements);
    assert_eq!(union_find.components(), elements);
    for element in 0..elements {
        assert_eq!(union_find.representative(element), element);
    }
    for element in 0..(elements / 2) {
        union_find.merge(element, elements - 1 - element);
    }
    for element in 0..(elements / 2 - 1) {
        union_find.merge(element, element + 1);
    }
    assert_eq!(union_find.components(), 1);
    for element in 0..elements {
        assert_eq!(union_find.representative(element), 7);
    }
    union_find.finalize();
    assert_eq!(union_find.components(), 1);
    for element in 0..elements {
        assert_eq!(union_find.component(element), 0);
    }
}