From 527c2d5bf419dd4db6d972732ba7e41ac34e99a1 Mon Sep 17 00:00:00 2001
From: spencerkrebs <krebsspencer@gmail.com>
Date: Sun, 12 Apr 2026 23:21:19 -0400
Subject: [PATCH] binary 2

---
 .DS_Store              | Bin 0 -> 6148 bytes
 find-min-in-rotated.py |  13 +++++++++++
 find-peak-element.py   |  17 ++++++++++++++
 first-and-last.py      |  50 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 80 insertions(+)
 create mode 100644 .DS_Store
 create mode 100644 find-min-in-rotated.py
 create mode 100644 find-peak-element.py
 create mode 100644 first-and-last.py

diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000000000000000000000000000000000000..5008ddfcf53c02e82d7eee2e57c38e5672ef89f6
GIT binary patch
literal 6148
zcmeH~Jr2S!425mzP>H1@V-^m;4Wg<&0T*E43hX&L&p$$qDprKhvt+--jT7}7np#A3
zem<@ulZcFPQ@L2!n>{z**<q8>++&mCkOWA81W14cNZ<zv;LbK1Poaz?KmsK2CSc!(
z0ynLxE!0092;Krf2c+FF_Fe*7ECH>lEfg7;MkzE(HCqgga^y>{tEnwC%0;vJ&^%eQ
zLs35+`xjp>T0<F0fCPF1$Cyrb|F7^5{eNG?83~ZUUlGt@xh*qZDeu<Z%US-OSsOPv
j)R!Z4KLME7ReXlK;d!wEw5GODWMKRea10D2@KpjYNUI8I

literal 0
HcmV?d00001

diff --git a/find-min-in-rotated.py b/find-min-in-rotated.py
new file mode 100644
index 00000000..0a044d87
--- /dev/null
+++ b/find-min-in-rotated.py
@@ -0,0 +1,13 @@
+class Solution:
+    def findMin(self, nums: List[int]) -> int:
+        left = 0
+        right = len(nums)-1
+
+        while left < right:
+            mid = left + (right - left)//2
+            if nums[mid] > nums[right]:
+                left = mid + 1
+            else:
+                right = mid
+
+        return nums[left]
\ No newline at end of file
diff --git a/find-peak-element.py b/find-peak-element.py
new file mode 100644
index 00000000..d0fe3e68
--- /dev/null
+++ b/find-peak-element.py
@@ -0,0 +1,17 @@
+class Solution:
+    def findPeakElement(self, nums: List[int]) -> int:
+        # -inf [1,2,1,3,5,6,4] -inf
+        #       l     m l lr
+        # -inf [1,2,1,3,5,6,7] -inf, 7 is the peak
+        #       l       l m l
+        left = 0
+        right = len(nums)-1
+        while left < right:
+            mid = left + (right - left)//2
+
+            if nums[mid] < nums[mid+1]:
+                left = mid + 1
+            else:
+                right = mid
+
+        return left
\ No newline at end of file
diff --git a/first-and-last.py b/first-and-last.py
new file mode 100644
index 00000000..f6687533
--- /dev/null
+++ b/first-and-last.py
@@ -0,0 +1,50 @@
+class Solution:
+    # wrong - if you do binary search, then find 1, and expand window -> that is o(n) bc array could be all same number like [8,8,8,8,..]
+        def searchRange(self, nums: List[int], target: int) -> List[int]:
+            lower_bound = self.binarySearchLower(nums, target)
+            if lower_bound == -1:
+                return [-1, -1]
+
+            upper_bound = self.binarySearchUpper(nums, target)
+
+            return [lower_bound, upper_bound]
+
+        def binarySearchLower(self,nums, target):
+            left = 0
+            right = len(nums)-1
+
+            while left <= right:
+                mid = left + (right-left)//2
+                if nums[mid]==target:
+                    # we're at lower
+                    if left == mid or nums[mid-1] < target:
+                        return mid
+                    else:
+                        right = mid - 1 
+                elif nums[mid] < target:
+                    left = mid + 1
+                else:
+                    right = mid-1
+            
+            return -1
+
+        def binarySearchUpper(self,nums, target):
+            left = 0
+            right = len(nums)-1
+
+# [5,7,7,8,8,8,10]
+ #.l     l m    r
+            while left <= right:
+                mid = left + (right-left)//2
+                if nums[mid]==target:
+                    # we're at upper bound 
+                    if right == mid or nums[mid+1] > target:
+                        return mid
+                    else:
+                        left = mid + 1 
+                elif nums[mid] < target:
+                    left = mid + 1
+                else:
+                    right = mid-1
+            
+            return -1
\ No newline at end of file