38: pandigital multiples

38_pandigital_multiples/main.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+	"strconv"
+)
+
+func main() {
+	num := 0
+	for x := 9487; x >= 9234; x-- {
+		res := 100002 * x
+		if isPandigital(strconv.Itoa(res)) {
+			num = res
+			break
+		}
+	}
+	fmt.Println("num:", num)
+}
+
+func isPandigital(s string) bool {
+	var ss []string
+	for _, c := range s {
+		ss = append(ss, string(c))
+	}
+	sort.Strings(ss)
+	s = ""
+	for _, c := range ss {
+		s += c
+	}
+	return s == "123456789"
+}

38_pandigital_multiples/main_test.go

@@ -0,0 +1,37 @@
+package main
+
+import "testing"
+
+func Test_isPandigital(t *testing.T) {
+	type args struct {
+		s string
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{
+			"912345678",
+			args{"912345678"},
+			true,
+		},
+		{
+			"12345678",
+			args{"12345678"},
+			false,
+		},
+		{
+			"812349756",
+			args{"812349756"},
+			true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := isPandigital(tt.args.s); got != tt.want {
+				t.Errorf("isPandigital() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}