Range addition

#[test]
fn t1() {
    let start = std::time::Instant::now();
    let val = Solution::get_modified_array(5, vec![vec![1, 3, 2], vec![2, 4, 3], vec![0, 2, -2]]);
    let expected = vec![-2, 0, 3, 5, 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::get_modified_array(10, vec![vec![2, 4, 6], vec![5, 6, 8], vec![1, 9, -4]]);
    let expected = vec![0, -4, 2, 2, 2, 4, 4, -4, -4, -4];
    log_result!(val == expected, "t2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t3() {
    let start = std::time::Instant::now();
    let val = Solution::get_modified_array(5, (vec![] as Vec<Vec<i32>>));
    let expected = vec![0, 0, 0, 0, 0];
    log_result!(val == expected, "t3", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t4() {
    let start = std::time::Instant::now();
    let val = Solution::get_modified_array(3, vec![vec![0, 0, 1], vec![1, 1, 2], vec![2, 2, 3]]);
    let expected = vec![1, 2, 3];
    log_result!(val == expected, "t4", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t5() {
    let start = std::time::Instant::now();
    let val = Solution::get_modified_array(4, vec![vec![0, 3, 5], vec![0, 3, -2]]);
    let expected = vec![3, 3, 3, 3];
    log_result!(val == expected, "t5", start, &expected, &val);
    assert_eq!(val, expected);
}