diff --git a/20201117/main.go b/20201117/main.go
new file mode 100644
index 0000000..cc7a52c
--- /dev/null
+++ b/20201117/main.go
@@ -0,0 +1,66 @@
+package main
+
+import (
+	"sort"
+)
+
+//56. 合并区间
+//
+//给出一个区间的集合，请合并所有重叠的区间。
+//
+//
+//示例 1:
+//
+//输入: intervals = [[1,3],[2,6],[8,10],[15,18]]
+//输出: [[1,6],[8,10],[15,18]]
+//解释: 区间 [1,3] 和 [2,6] 重叠, 将它们合并为 [1,6].
+//示例 2:
+//
+//输入: intervals = [[1,4],[4,5]]
+//输出: [[1,5]]
+//解释: 区间 [1,4] 和 [4,5] 可被视为重叠区间。
+//注意：输入类型已于2019年4月15日更改。 请重置默认代码定义以获取新方法签名。
+//
+//提示：
+//intervals[i][0] <= intervals[i][1]
+
+func main() {
+
+}
+
+func mergeAndSortSlices(src [][]int) []int {
+	var ret []int
+	for _, s := range src {
+		for _, n := range s {
+			ret = append(ret, n)
+		}
+	}
+	sort.Ints(ret)
+	return ret
+}
+
+func pickInterval(src []int) [][]int {
+	left := 0
+	i := 1
+	var ret [][]int
+	for {
+		if i+1 > len(src)-1 {
+			if left < len(src) {
+				ret = append(ret, [][]int{{src[left], src[i]}}...)
+			}
+			break
+		}
+		if src[i]+1 < src[i+1] {
+			ret = append(ret, [][]int{{src[left], src[i+1]}}...)
+			i += 2
+			left = i
+			continue
+		}
+		i++
+	}
+	return ret
+}
+
+func merge(src [][]int) [][]int {
+	return pickInterval(mergeAndSortSlices(src))
+}
diff --git a/20201117/main_test.go b/20201117/main_test.go
new file mode 100644
index 0000000..448c7f0
--- /dev/null
+++ b/20201117/main_test.go
@@ -0,0 +1,103 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_mergeSlices(t *testing.T) {
+	type args struct {
+		src [][]int
+	}
+	tests := []struct {
+		name string
+		args args
+		want []int
+	}{
+		{
+			"case_1",
+			args{[][]int{{1, 3}, {2, 6}, {8, 10}, {15, 18}}},
+			[]int{1, 2, 3, 6, 8, 10, 15, 18},
+		},
+		{
+			"case_2",
+			args{[][]int{{1, 4}, {4, 5}}},
+			[]int{1, 4, 4, 5},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := mergeAndSortSlices(tt.args.src); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("mergeAndSortSlices() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_pickInterval(t *testing.T) {
+	type args struct {
+		src []int
+	}
+	tests := []struct {
+		name string
+		args args
+		want [][]int
+	}{
+		{
+			"case_1",
+			args{[]int{1, 2, 3, 6, 8, 10, 15, 18}},
+			[][]int{{1, 6}, {8, 10}, {15, 18}},
+		},
+		{
+			"case_2",
+			args{[]int{1, 1}},
+			[][]int{{1, 1}},
+		},
+		{
+			"case_3",
+			args{[]int{1, 2, 2, 3, 6, 8, 10, 15, 18}},
+			[][]int{{1, 6}, {8, 10}, {15, 18}},
+		},
+		{
+			"case_4",
+			args{[]int{1, 4, 4, 5}},
+			[][]int{{1, 5}},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := pickInterval(tt.args.src); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("pickInterval() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_merge(t *testing.T) {
+	type args struct {
+		src [][]int
+	}
+	tests := []struct {
+		name string
+		args args
+		want [][]int
+	}{
+		{
+			"case_1",
+			args{[][]int{{1, 3}, {2, 6}, {8, 10}, {15, 18}}},
+			[][]int{{1, 6}, {8, 10}, {15, 18}},
+		},
+		{
+			"case_2",
+			args{[][]int{{1, 4}, {4, 5}}},
+			[][]int{{1, 5}},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := merge(tt.args.src); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("merge() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}