From 3069ee579659af76f4d9ac5174ee98a2b20db1be Mon Sep 17 00:00:00 2001
From: Micke <155267459+reallesee@users.noreply.github.com>
Date: Sat, 12 Jul 2025 20:30:56 +0200
Subject: [PATCH 1/4] Optimize is_subsequence function to linear time
 complexity

---
 vm/src/utils.rs | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/vm/src/utils.rs b/vm/src/utils.rs
index 6a6a284ee6..f9d7d77216 100644
--- a/vm/src/utils.rs
+++ b/vm/src/utils.rs
@@ -28,14 +28,20 @@ macro_rules! any_box {
 }
 
 pub fn is_subsequence<T: PartialEq>(subsequence: &[T], mut sequence: &[T]) -> bool {
-    for search in subsequence {
-        if let Some(index) = sequence.iter().position(|element| search == element) {
-            sequence = &sequence[index + 1..];
-        } else {
-            return false;
+    if subsequence.is_empty() {
+        return true;
+    }
+    
+    let mut subseq_idx = 0;
+    for element in sequence {
+        if element == &subsequence[subseq_idx] {
+            subseq_idx += 1;
+            if subseq_idx == subsequence.len() {
+                return true;
+            }
         }
     }
-    true
+    false
 }
 
 pub fn from_relocatable_to_indexes(relocatable: Relocatable) -> (usize, usize) {

From de91b5b155daa163b89aa6f261fe3ea9edbc8cf2 Mon Sep 17 00:00:00 2001
From: Micke <155267459+reallesee@users.noreply.github.com>
Date: Fri, 18 Jul 2025 13:35:53 +0200
Subject: [PATCH 2/4] fix: make is_subsequence panic-safe by using pattern
 matching

---
 vm/src/utils.rs | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/vm/src/utils.rs b/vm/src/utils.rs
index f9d7d77216..6be26cd7b4 100644
--- a/vm/src/utils.rs
+++ b/vm/src/utils.rs
@@ -28,17 +28,16 @@ macro_rules! any_box {
 }
 
 pub fn is_subsequence<T: PartialEq>(subsequence: &[T], mut sequence: &[T]) -> bool {
-    if subsequence.is_empty() {
-        return true;
-    }
-    
     let mut subseq_idx = 0;
     for element in sequence {
-        if element == &subsequence[subseq_idx] {
-            subseq_idx += 1;
-            if subseq_idx == subsequence.len() {
-                return true;
+        match subsequence.get(&subseq_idx) {
+            Some(sub_elem) if element == &sub_elem => {
+                subseq_idx += 1;
+                if subseq_idx == subsequence.len() {
+                    return true;
+                }
             }
+            None => return false
         }
     }
     false

From 9c26dc2245aa59217112572b8ccec5b8edb46998 Mon Sep 17 00:00:00 2001
From: Micke <155267459+reallesee@users.noreply.github.com>
Date: Fri, 18 Jul 2025 18:06:05 +0200
Subject: [PATCH 3/4] Update utils.rs

---
 vm/src/utils.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vm/src/utils.rs b/vm/src/utils.rs
index 6be26cd7b4..2184ef3acc 100644
--- a/vm/src/utils.rs
+++ b/vm/src/utils.rs
@@ -37,7 +37,7 @@ pub fn is_subsequence<T: PartialEq>(subsequence: &[T], mut sequence: &[T]) -> bo
                     return true;
                 }
             }
-            None => return false
+            None => return true
         }
     }
     false

From c0cce9b60cfc0b4fac54352908c7191699330a2f Mon Sep 17 00:00:00 2001
From: Micke <155267459+reallesee@users.noreply.github.com>
Date: Fri, 18 Jul 2025 21:16:26 +0200
Subject: [PATCH 4/4] fix: restore empty check and fix None case handling in
 is_subsequence function

---
 vm/src/utils.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/vm/src/utils.rs b/vm/src/utils.rs
index 2184ef3acc..24d0120572 100644
--- a/vm/src/utils.rs
+++ b/vm/src/utils.rs
@@ -28,6 +28,10 @@ macro_rules! any_box {
 }
 
 pub fn is_subsequence<T: PartialEq>(subsequence: &[T], mut sequence: &[T]) -> bool {
+    if subsequence.is_empty() {
+        return true;
+    }
+    
     let mut subseq_idx = 0;
     for element in sequence {
         match subsequence.get(&subseq_idx) {
@@ -37,7 +41,7 @@ pub fn is_subsequence<T: PartialEq>(subsequence: &[T], mut sequence: &[T]) -> bo
                     return true;
                 }
             }
-            None => return true
+            None => return false
         }
     }
     false