From 027abd6ad5a8c9ac90b786f1574899767cab8057 Mon Sep 17 00:00:00 2001
From: dudaodong <lanliddd.2007@163.com>
Date: Thu, 30 Mar 2023 11:54:20 +0800
Subject: [PATCH] feat: add IsPrime

---
 mathutil/mathutil.go              | 16 ++++++++++++++++
 mathutil/mathutil_exmaple_test.go | 18 ++++++++++++++++++
 mathutil/mathutil_test.go         | 11 +++++++++++
 3 files changed, 45 insertions(+)

diff --git a/mathutil/mathutil.go b/mathutil/mathutil.go
index 8642a36..b404ebe 100644
--- a/mathutil/mathutil.go
+++ b/mathutil/mathutil.go
@@ -240,3 +240,19 @@ func PointDistance(x1, y1, x2, y2 float64) float64 {
 
 	return math.Sqrt(c)
 }
+
+// IsPrimes checks if number is prime number.
+// Play: todo
+func IsPrime(n int) bool {
+	if n < 2 {
+		return false
+	}
+
+	for i := 2; i <= int(math.Sqrt(float64(n))); i++ {
+		if n%i == 0 {
+			return false
+		}
+	}
+
+	return true
+}
diff --git a/mathutil/mathutil_exmaple_test.go b/mathutil/mathutil_exmaple_test.go
index c860d12..56a3bae 100644
--- a/mathutil/mathutil_exmaple_test.go
+++ b/mathutil/mathutil_exmaple_test.go
@@ -263,3 +263,21 @@ func ExamplePointDistance() {
 	// Output:
 	// 5
 }
+
+func ExampleIsPrime() {
+	result1 := IsPrime(-1)
+	result2 := IsPrime(0)
+	result3 := IsPrime(1)
+	result4 := IsPrime(2)
+
+	fmt.Println(result1)
+	fmt.Println(result2)
+	fmt.Println(result3)
+	fmt.Println(result4)
+
+	// Output:
+	// false
+	// false
+	// false
+	// true
+}
diff --git a/mathutil/mathutil_test.go b/mathutil/mathutil_test.go
index a7e033a..b8b8e28 100644
--- a/mathutil/mathutil_test.go
+++ b/mathutil/mathutil_test.go
@@ -200,3 +200,14 @@ func TestPointDistance(t *testing.T) {
 
 	assert.Equal(float64(5), result1)
 }
+
+func TestIsPrime(t *testing.T) {
+	assert := internal.NewAssert(t, "TestIsPrime")
+
+	assert.Equal(false, IsPrime(-1))
+	assert.Equal(false, IsPrime(0))
+	assert.Equal(false, IsPrime(1))
+	assert.Equal(true, IsPrime(2))
+	assert.Equal(true, IsPrime(3))
+	assert.Equal(false, IsPrime(4))
+}