Minimum prefix removal to make array strictly increasing

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

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

#[test]
fn t3() {
    let start = std::time::Instant::now();
    let val = Solution::minimum_prefix_length(vec![1, 2, 3, 4]);
    let expected = 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::minimum_prefix_length(vec![5]);
    let expected = 0;
    log_result!(val == expected, "t4", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t5() {
    let start = std::time::Instant::now();
    let val = Solution::minimum_prefix_length(vec![3, 2, 1]);
    let expected = 2;
    log_result!(val == expected, "t5", start, &expected, &val);
    assert_eq!(val, expected);
}