From e3057136ef73209229b3abf58fdc5e8f806e60f9 Mon Sep 17 00:00:00 2001
From: irrawaddy28 <xad890@gmail.com>
Date: Wed, 8 Oct 2025 21:43:12 -0700
Subject: [PATCH] completed all changes

---
 Problem_1.py | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 Problem_1.py

diff --git a/Problem_1.py b/Problem_1.py
new file mode 100644
index 00000000..0d29c338
--- /dev/null
+++ b/Problem_1.py
@@ -0,0 +1,44 @@
+'''
+    Given an array of contiguous integers of size N-1, where the elements of the array could be anywhere in the range [1,N], find the missing element in the array
+
+    Example 1:
+        Input = [2,3,4,5,6,7,9,10]
+        Output = 8
+
+    Example 2:
+        Input = [2,3,5,6,7,9,10]
+        Output = 4
+
+    Example 3:
+        Input = [2]
+        Output = -1
+'''
+def search_missing(A):
+
+    N = len(A)
+    if N <= 1:
+        return -1
+    if A[1] != A[0] + 1:
+        return A[0] + 1
+    if A[N-1] != A[N-2] + 1:
+        return A[N-2] + 1
+
+    s=1
+    e=N-2
+    while s <= e:
+        mid = s + (e - s)//2
+        if (A[mid] + 1) != A[mid+1]:
+            return A[mid] + 1
+        if A[s] - s == A[mid]-mid: # left half is continguous
+            s = mid + 1
+        else: # right half is contiguous
+            e = mid - 1
+
+A = [2,3,4,5,6,7,9,10]
+print(search_missing(A))
+
+A = [2,3,5,6,7,9,10]
+print(search_missing(A))
+
+A = [2]
+print(search_missing(A))
\ No newline at end of file