From adbd4ff26bb9a62b0d5e6a1a50575f968066c55d Mon Sep 17 00:00:00 2001
From: Xevion <xevion@xevion.dev>
Date: Mon, 2 Oct 2023 20:39:41 -0500
Subject: [PATCH] Proper two pointer implementation

im rarted
---
 median-of-two-sorted-arrays/src/main.rs | 102 +++++-------------------
 1 file changed, 22 insertions(+), 80 deletions(-)

diff --git a/median-of-two-sorted-arrays/src/main.rs b/median-of-two-sorted-arrays/src/main.rs
index 9778786..43e96ad 100644
--- a/median-of-two-sorted-arrays/src/main.rs
+++ b/median-of-two-sorted-arrays/src/main.rs
@@ -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])
-    // );
 }