56 没有深入理解题意，准备大改程序结构

Author: aQua

Algorithms/0056.merge-intervals/README.md

@@ -3,10 +3,11 @@
 ## 题目
 Given a collection of intervals, merge all overlapping intervals.
 
-
+```
 For example,
 Given [1,3],[2,6],[8,10],[15,18],
 return [1,6],[8,10],[15,18].
+```
 ## 解题思路
 
 见程序注释

Algorithms/0056.merge-intervals/merge-intervals.go

@@ -1,5 +1,54 @@
 package Problem0056
 
+// Interval Definition for an interval.
+type Interval struct {
+	Start int
+	End   int
+}
+
 func merge(intervals []Interval) []Interval {
+	if len(intervals) <= 1 {
+		return intervals
+	}
+
+	res := make([]Interval, 0, len(intervals))
+	temp := intervals[0]
+
+	for i := 1; i < len(intervals); i++ {
+		if isOverlap(temp, intervals[i]) {
+			temp = mergeInterval(temp, intervals[i])
+			continue
+		}
+		res = append(res, temp)
+		temp = intervals[i]
+	}
+
+	res = append(res, temp)
+
+	return res
+}
+
+func isOverlap(a, b Interval) bool {
+	return (a.Start <= b.Start && b.Start <= a.End) || (a.Start <= b.End && b.End <= a.End) || (b.Start <= a.Start && a.Start <= b.End)
+}
+
+func mergeInterval(a, b Interval) Interval {
+	return Interval{
+		Start: min(a.Start, b.Start),
+		End:   max(a.End, b.End),
+	}
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
 
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
 }

Algorithms/0056.merge-intervals/merge-intervals_test.go

@@ -1,8 +1,8 @@
 package Problem0056
 
 import (
-	"testing"
 	"fmt"
+	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -19,7 +19,7 @@ type para struct {
 
 // ans 是答案
 type ans struct {
-	one  []Interval 
+	one []Interval
 }
 
 func Test_Problem0056(t *testing.T) {
@@ -28,21 +28,93 @@ func Test_Problem0056(t *testing.T) {
 	qs := []question{
 
 		question{
-			para{
-					,
+			para{[]Interval{
+				Interval{2, 3},
+				Interval{4, 5},
+				Interval{6, 7},
+				Interval{8, 9},
+				Interval{1, 10},
+			},
+			},
+			ans{[]Interval{
+				Interval{1, 10},
+			},
+			},
+		},
+
+		question{
+			para{[]Interval{
+				Interval{1, 4},
+				Interval{0, 5},
+			},
+			},
+			ans{[]Interval{
+				Interval{0, 5},
+			},
+			},
+		},
+
+		question{
+			para{[]Interval{
+				Interval{1, 4},
+				Interval{2, 5},
+			},
+			},
+			ans{[]Interval{
+				Interval{1, 5},
 			},
-			ans{
-					,
 			},
 		},
-	
+
+		question{
+			para{[]Interval{
+				Interval{1, 3},
+				Interval{2, 6},
+				Interval{8, 10},
+				Interval{15, 18},
+			}},
+			ans{[]Interval{
+				Interval{1, 6},
+				Interval{8, 10},
+				Interval{15, 18},
+			},
+			},
+		},
+
+		question{
+			para{[]Interval{
+				Interval{1, 6},
+			},
+			},
+			ans{[]Interval{
+				Interval{1, 6},
+			},
+			},
+		},
+
 		// 如需多个测试，可以复制上方元素。
 	}
 
 	for _, q := range qs {
 		a, p := q.ans, q.para
 		fmt.Printf("~~%v~~\n", p)
 
-		ast.Equal(a.one, merge(p.  ), "输入:%v", p)
+		ast.Equal(a.one, merge(p.intervals), "输入:%v", p)
 	}
 }
+
+func Test_min(t *testing.T) {
+	ast := assert.New(t)
+
+	actual := min(1, 0)
+	expected := 0
+	ast.Equal(expected, actual)
+}
+
+func Test_max(t *testing.T) {
+	ast := assert.New(t)
+
+	actual := max(1, 0)
+	expected := 1
+	ast.Equal(expected, actual)
+}