20201203

20201202/main.go

@@ -14,7 +14,7 @@ func main() {
 
 }
 
-func RomaToDigit(s string) int {
+func romaToDigit(s string) int {
 	l := len(s)
 	ret := 0
 	for i := 0; i < l; i++ {

20201202/main_test.go

@@ -36,11 +36,21 @@ func TestRomaToDigit(t *testing.T) {
 			args{"MCMXCIV"},
 			1994,
 		},
+		{
+			"test6",
+			args{"CMXCIX"},
+			999,
+		},
+		{
+			"test7",
+			args{"XLIX"},
+			49,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := RomaToDigit(tt.args.s); got != tt.want {
-				t.Errorf("RomaToDigit() = %v, want %v", got, tt.want)
+			if got := romaToDigit(tt.args.s); got != tt.want {
+				t.Errorf("romaToDigit() = %v, want %v", got, tt.want)
 			}
 		})
 	}

20201203/main.go

@@ -0,0 +1,30 @@
+package main
+
+func main() {
+
+}
+
+func goodPairsCount(src []int) int {
+	count := 0
+	l := len(src)
+	for i := 0; i < l; i++ {
+		for j := i + 1; j < l; j++ {
+			if src[i] == src[j] {
+				count++
+			}
+		}
+	}
+	return count
+}
+
+func goodPairsCount2(src []int) int {
+	m := make(map[int]int)
+	for _, n := range src {
+		m[n] += 1
+	}
+	count := 0
+	for _, v := range m {
+		count += v * (v - 1) / 2
+	}
+	return count
+}

20201203/main_test.go

@@ -0,0 +1,71 @@
+package main
+
+import "testing"
+
+func Test_goodPairsCount(t *testing.T) {
+	type args struct {
+		src []int
+	}
+	tests := []struct {
+		name string
+		args args
+		want int
+	}{
+		{
+			"test1",
+			args{[]int{1, 2, 3, 1, 1, 3}},
+			4,
+		},
+		{
+			"test2",
+			args{[]int{1, 1, 1, 1}},
+			6,
+		},
+		{
+			"test3",
+			args{[]int{1, 2, 3}},
+			0,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := goodPairsCount(tt.args.src); got != tt.want {
+				t.Errorf("goodPairsCount() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_goodPairsCount2(t *testing.T) {
+	type args struct {
+		src []int
+	}
+	tests := []struct {
+		name string
+		args args
+		want int
+	}{
+		{
+			"test1",
+			args{[]int{1, 2, 3, 1, 1, 3}},
+			4,
+		},
+		{
+			"test2",
+			args{[]int{1, 1, 1, 1}},
+			6,
+		},
+		{
+			"test3",
+			args{[]int{1, 2, 3}},
+			0,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := goodPairsCount2(tt.args.src); got != tt.want {
+				t.Errorf("goodPairsCount() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}