Minimize maximum pair sum in array

#[test]
fn t1() {
    let start = std::time::Instant::now();
    let val = Solution::min_pair_sum(vec![3, 5, 2, 3]);
    let expected = 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::min_pair_sum(vec![3, 5, 4, 2, 4, 6]);
    let expected = 8;
    log_result!(val == expected, "t2", start, &expected, &val);
    assert_eq!(val, expected);
}

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

#[test]
fn t4() {
    let start = std::time::Instant::now();
    let val = Solution::min_pair_sum(vec![1, 1, 1, 1]);
    let expected = 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::min_pair_sum(vec![1, 5, 3, 7]);
    let expected = 8;
    log_result!(val == expected, "t5", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t6() {
    let start = std::time::Instant::now();
    let val = Solution::min_pair_sum(vec![10, 20, 30, 40]);
    let expected = 50;
    log_result!(val == expected, "t6", start, &expected, &val);
    assert_eq!(val, expected);
}