N repeated element in size 2n array

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

#[test]
fn t2() {
    let start = std::time::Instant::now();
    let val = Solution::repeated_n_times(vec![2, 1, 2, 5, 3, 2]);
    let expected = 2;
    log_result!(val == expected, "t2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t3() {
    let start = std::time::Instant::now();
    let val = Solution::repeated_n_times(vec![5, 1, 5, 2, 5, 3, 5, 4]);
    let expected = 5;
    log_result!(val == expected, "t3", start, &expected, &val);
    assert_eq!(val, expected);
}

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

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