Shuffle the array

#[test]
fn t1() {
    let start = std::time::Instant::now();
    let val = Solution::shuffle(vec![2, 5, 1, 3, 4, 7], 3);
    let expected = vec![2, 3, 5, 4, 1, 7];
    log_result!(val == expected, "t1", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t2() {
    let start = std::time::Instant::now();
    let val = Solution::shuffle(vec![1, 2, 3, 4, 4, 3, 2, 1], 4);
    let expected = vec![1, 4, 2, 3, 3, 2, 4, 1];
    log_result!(val == expected, "t2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t3() {
    let start = std::time::Instant::now();
    let val = Solution::shuffle(vec![1, 1, 2, 2], 2);
    let expected = vec![1, 2, 1, 2];
    log_result!(val == expected, "t3", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t4() {
    let start = std::time::Instant::now();
    let val = Solution::shuffle(vec![1, 2], 1);
    let expected = vec![1, 2];
    log_result!(val == expected, "t4", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t5() {
    let start = std::time::Instant::now();
    let val = Solution::shuffle(vec![5, 4, 3, 2, 1, 6, 7, 8, 9, 10], 5);
    let expected = vec![5, 6, 4, 7, 3, 8, 2, 9, 1, 10];
    log_result!(val == expected, "t5", start, &expected, &val);
    assert_eq!(val, expected);
}