From 5374dd7375d3e2acaffc00907920f42bf5d8dc23 Mon Sep 17 00:00:00 2001
From: Ilya Smyshlyaev <smyshlyaev.il@yandex.ru>
Date: Tue, 20 Sep 2022 01:56:29 +0300
Subject: [PATCH] add missing number finder and some other changes

---
 .DS_Store               | Bin 6148 -> 8196 bytes
 main.go                 |   7 +++++++
 missing/missing.go      |  24 ++++++++++++++++++++++++
 missing/missing_test.go |   1 +
 rotation/rotation.go    |   1 +
 unique/findunique.go    |  12 ++++++++++--
 6 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 missing/missing.go
 create mode 100644 missing/missing_test.go

diff --git a/.DS_Store b/.DS_Store
index 118ac0472abe514d2ade1563a9225627e2403296..bff0db87707986bbf1e3f9762454f78a3e0a213a 100644
GIT binary patch
delta 372
zcmZoMXmOBWU|?W$DortDU;r^WfEYvza8E20o2aKKDgu%R@);PC7)lw^8RCI-=4L?-
zF_z5=9KFno**Q2SHn5n3lyL(k;~7#IQjwK1<ay@gCnx3PCxJ`_;`Km0?>`tYFl^>w
zImB4c1~fOHL60F9NT#4FXZ#6Nt_M>NWU~WRB{F0(<N?(Kb)l+ea6~p7$mV1SVsHhD
zx-j?xX^;)*=65qNa3L(%e46zMqdFVVr+Gj-3W0Pgstru(2={DWD3Z)Pv4KaB87Kw>
k65K$-6%=;B@cGU>nP0?nvOf<82Qc_R!OE~Xo@Wj-0FLilDF6Tf

delta 132
zcmZp1XfcprU|?W$DortDU=RQ@Ie-{Mvv5r;6q~50D9R6#2a6>!lrmH?RC(s)CvPlV
z&dkU^`Jtf5<}iVEjGHG2J!G6%60w+_gF}!Rr~wEBxPgQ#$e@jd-<c=#%Xor}Wnh9>
N0kV~0b3D%+W&krE7qS2V

diff --git a/main.go b/main.go
index 7905807..2712b7b 100644
--- a/main.go
+++ b/main.go
@@ -1,5 +1,12 @@
 package main
 
+import (
+	"fmt"
+	"gotest/missing"
+)
+
 func main() {
 
+	fmt.Print(missing.FindNumber([]int{1, 3, 5, 2, 6, 7, -9, 8, 4}))
+
 }
diff --git a/missing/missing.go b/missing/missing.go
new file mode 100644
index 0000000..31611b3
--- /dev/null
+++ b/missing/missing.go
@@ -0,0 +1,24 @@
+package missing
+
+import "fmt"
+
+func FindNumber(A []int) int {
+
+	var elements_sum int
+
+	for i := 0; i < len(A); i++ {
+
+		if A[i] < 0 || A[i] > 100000 {
+			fmt.Print("array has negative element or longer than expected")
+			return A[i]
+		} else {
+			elements_sum = elements_sum + A[i]
+		}
+
+	}
+
+	nums_sum := (len(A) + 1) * (len(A) + 2) / 2
+
+	return nums_sum - elements_sum
+
+}
diff --git a/missing/missing_test.go b/missing/missing_test.go
new file mode 100644
index 0000000..4142715
--- /dev/null
+++ b/missing/missing_test.go
@@ -0,0 +1 @@
+package missing_test
diff --git a/rotation/rotation.go b/rotation/rotation.go
index d10fcc1..c275f08 100644
--- a/rotation/rotation.go
+++ b/rotation/rotation.go
@@ -1,3 +1,4 @@
+// Циклическая ротация
 package rotation
 
 func Rotation(A []int, K int) []int {
diff --git a/unique/findunique.go b/unique/findunique.go
index 045935d..218b4f4 100644
--- a/unique/findunique.go
+++ b/unique/findunique.go
@@ -1,10 +1,18 @@
+// Чудные вхождения в массив
 package unique
 
+import "fmt"
+
 func FindUnique(A []int) int {
 	var result int
 
-	for i := 0; i < len(A); i++ {
-		result = result ^ A[i]
+	if len(A)%2 != 0 {
+		for i := 0; i < len(A); i++ {
+			//xor use
+			result = result ^ A[i]
+		}
+	} else {
+		fmt.Println("the number of elements is even")
 	}
 
 	return result