From 0f02ef8e650680114997423118ec9a4e59f633f8 Mon Sep 17 00:00:00 2001
From: Matej Focko <me@mfocko.xyz>
Date: Mon, 19 Aug 2024 21:19:11 +0200
Subject: [PATCH] =?UTF-8?q?go:=20add=20=C2=AB162.=20Find=20Peak=20Element?=
 =?UTF-8?q?=C2=BB?=
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Signed-off-by: Matej Focko <me@mfocko.xyz>
---
 go/find-peak-element.go | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 go/find-peak-element.go

diff --git a/go/find-peak-element.go b/go/find-peak-element.go
new file mode 100644
index 0000000..bfcf169
--- /dev/null
+++ b/go/find-peak-element.go
@@ -0,0 +1,31 @@
+package main
+
+func findPeakElement(nums []int) int {
+	length := len(nums)
+
+	check := func(i int) bool {
+		return (i == 0 || nums[i-1] < nums[i]) && (i == length-1 || nums[i] > nums[i+1])
+	}
+
+	if check(0) {
+		return 0
+	} else if check(length - 1) {
+		return length - 1
+	}
+
+	left, right := 1, length-2
+
+	for left <= right {
+		mid := (left + right) / 2
+
+		if check(mid) {
+			return mid
+		} else if nums[mid] < nums[mid-1] {
+			right = mid - 1
+		} else if nums[mid] < nums[mid+1] {
+			left = mid + 1
+		}
+	}
+
+	panic("unreachable: peak element is guaranteed")
+}