special pythagorean triplet

special_dpythagorean_triplet/main.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	got := SplitIntegerIntoThree(1000)
+	product := 0
+	for _, v := range got {
+		if IsPythagoreanTriplet(v) {
+			fmt.Println("Pythagorean triplet ", v)
+			product = GetProduct(v)
+			break
+		}
+	}
+	fmt.Println("product:", product)
+}
+
+func SplitIntegerIntoThree(src int) [][]int {
+	var ret [][]int
+	x := 1
+	for {
+		left1 := src - x
+		if left1 < x {
+			break
+		}
+		y := x + 1
+		for {
+			var r []int
+			r = append(r, x)
+			left2 := left1 - y
+			if left2 < y+1 {
+				break
+			}
+			r = append(r, y)
+			r = append(r, left2)
+			ret = append(ret, r)
+			y++
+		}
+		x++
+	}
+	return ret
+}
+
+func IsPythagoreanTriplet(ns []int) bool {
+	if len(ns) != 3 {
+		return false
+	}
+	var squares []int
+	for _, v := range ns {
+		squares = append(squares, v*v)
+	}
+	if squares[0]+squares[1] == squares[2] {
+		return true
+	}
+	return false
+}
+
+func GetProduct(ns []int) int {
+	product := 1
+	for _, v := range ns {
+		product = product * v
+	}
+	return product
+}

special_dpythagorean_triplet/special_pythagorean_triplet_test.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestSplitInteger(t *testing.T) {
+	tt := []struct {
+		name string
+		src  int
+		want [][]int
+	}{
+		{
+			"5-3",
+			6,
+			[][]int{
+				{1, 2, 3},
+			},
+		},
+		{
+			"10-3",
+			10,
+			[][]int{
+				{1, 2, 7},
+				{1, 3, 6},
+				{1, 4, 5},
+				{2, 3, 5},
+			},
+		},
+		{
+			"11-3",
+			11,
+			[][]int{
+				{1, 2, 8},
+				{1, 3, 7},
+				{1, 4, 6},
+				{2, 3, 6},
+				{2, 4, 5},
+			},
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			got := SplitIntegerIntoThree(tc.src)
+			if !reflect.DeepEqual(got, tc.want) {
+				t.Errorf("SplitInteger(%d)=%v, want %v", tc.src, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestIsPythagoreanTriplet(t *testing.T) {
+	tt := []struct {
+		name  string
+		input []int
+		want  bool
+	}{
+		{
+			"3,4",
+			[]int{3, 4},
+			false,
+		},
+		{
+			"3,4,5,6",
+			[]int{3, 4, 5, 6},
+			false,
+		},
+		{
+			"3,4,5",
+			[]int{3, 4, 5},
+			true,
+		},
+		{
+			"3,4,6",
+			[]int{3, 4, 6},
+			false,
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			got := IsPythagoreanTriplet(tc.input)
+			if got != tc.want {
+				t.Errorf("IsPythagoreanTriplet(%v)=%v, want %v", tc.input, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestGetProduct(t *testing.T) {
+	tt := []struct {
+		name  string
+		input []int
+		want  int
+	}{
+		{
+			"0",
+			[]int{0, 1, 1},
+			0,
+		},
+		{
+			"2",
+			[]int{2, 1, 1},
+			2,
+		},
+		{
+			"3",
+			[]int{2, 3, 4},
+			24,
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			got := GetProduct(tc.input)
+			if got != tc.want {
+				t.Errorf("GetProduct(%v)=%d, want %d", tc.input, got, tc.want)
+			}
+		})
+	}
+}