Proper two pointer implementation

im rarted
This commit is contained in:
2023-10-02 20:39:41 -05:00
parent 0ac04eb134
commit adbd4ff26b

View File

@@ -1,102 +1,44 @@
struct Solution {}
impl Solution {
pub fn find_median(v: Vec<i32>) -> f64 {
let middle = (v.len() / 2) - 1;
if v.len() % 2 == 1 {
return v[middle] as f64;
}
(v[middle] + v[middle + 1]) as f64 / 2.0
}
pub fn find_median_sorted_arrays(a: Vec<i32>, b: Vec<i32>) -> f64 {
let mut i = 0;
let mut j = 0;
let mut current = 0;
let mut previous = 0;
let mut count = 0;
let is_average = (a.len() + b.len()) % 2 == 0;
let target = (a.len() + b.len()) / 2;
let (a_length, b_length) = (a.len(), b.len());
let (mut a_pointer, mut b_pointer, mut current, mut previous) = (0, 0, 0, 0);
if target == 0 {
if a.len() == 0 && b.len() == 0 {
return 0.0;
} else if a.len() == 0 {
return b[0] as f64;
} else if b.len() == 0 {
return a[0] as f64;
}
}
if a.len() == 0 {
return Solution::find_median(b);
} else if b.len() == 0 {
return Solution::find_median(a);
}
println!("current={current} prev={previous} i={i} j={j}");
while count <= target {
for _ in 0..=((a_length+b_length)/2) {
previous = current;
if i < a.len() && a[i] <= b[j] {
current = a[i];
i += 1;
if a_pointer != a_length && b_pointer != b_length {
// Main merge point (as long as both arrays have space to iterate left)
if a[a_pointer] > b[b_pointer] {
current = b[b_pointer];
b_pointer += 1;
} else {
current = a[a_pointer];
a_pointer += 1;
}
} else if a_pointer < a_length {
// Other array has no more space to iterate
current = a[a_pointer];
a_pointer += 1;
} else {
current = b[j];
j += 1;
// Other array has no more space to iterate
current = b[b_pointer];
b_pointer += 1;
}
println!("current={current} prev={previous} i={i} j={j}");
// Case in which array A or B is composed entirely of smaller numbers (i.e. [1, 2] and [3, 4]) - join the last and first elements.
if i == target {
if is_average {
previous = current;
current = b[0];
}
break;
} else if j == target {
if is_average {
previous = current;
current = a[0];
}
break;
}
count += 1;
}
if is_average {
(current + previous) as f64 / 2.0
} else {
if (a_length + b_length) % 2 == 1 {
current as f64
} else {
(current + previous) as f64 / 2.0
}
}
}
fn main() {
// assert_eq!(
// Solution::find_median_sorted_arrays(vec![1, 3], vec![2]),
// 2.0
// );
// assert_eq!(
// Solution::find_median_sorted_arrays(vec![1, 2], vec![3, 4]),
// 2.5
// );
// println!(
// "{}",
// Solution::find_median_sorted_arrays(vec![0, 0, 0, 0, 0], vec![-1, 0, 0, 0, 0, 0, 1])
// );
println!(
"{}",
Solution::find_median_sorted_arrays(vec![1, 3], vec![2])
);
// println!(
// "{}",
// Solution::find_median_sorted_arrays(vec![3], vec![-1, -2])
// );
}