20201118

20201118/main.go

@@ -0,0 +1,22 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println(findMaxLine(65535))
+}
+
+func findMaxLine(n int32) int32 {
+	var ret int32
+	for {
+		if findNumber(ret) > n {
+			ret--
+			return ret
+		}
+		ret++
+	}
+}
+
+func findNumber(n int32) int32 {
+	return n * (n + 1) / 2
+}

20201118/main_test.go

@@ -0,0 +1,66 @@
+package main
+
+import "testing"
+
+func Test_findNumber(t *testing.T) {
+	type args struct {
+		n int32
+	}
+	tests := []struct {
+		name string
+		args args
+		want int32
+	}{
+		{
+			"1",
+			args{1},
+			1,
+		},
+		{
+			"2",
+			args{2},
+			3,
+		},
+		{
+			"4",
+			args{4},
+			10,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := findNumber(tt.args.n); got != tt.want {
+				t.Errorf("findNumber() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_findMaxLine(t *testing.T) {
+	type args struct {
+		n int32
+	}
+	tests := []struct {
+		name string
+		args args
+		want int32
+	}{
+		{
+			"5",
+			args{5},
+			2,
+		},
+		{
+			"8",
+			args{8},
+			3,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := findMaxLine(tt.args.n); got != tt.want {
+				t.Errorf("findMaxLine() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}