Update 0401

Author: halfrost

leetcode/0401.Binary-Watch/401. Binary Watch.go

@@ -5,6 +5,43 @@ import (
 	"strconv"
 )
 
+// 解法一
+func readBinaryWatch(num int) []string {
+	memo := make([]int, 60)
+	// count the number of 1 in a binary number
+	count := func(n int) int {
+		if memo[n] != 0 {
+			return memo[n]
+		}
+		originN, res := n, 0
+		for n != 0 {
+			n = n & (n - 1)
+			res++
+		}
+		memo[originN] = res
+		return res
+	}
+	// fmtMinute format minute 0:1 -> 0:01
+	fmtMinute := func(m int) string {
+		if m < 10 {
+			return "0" + strconv.Itoa(m)
+		}
+		return strconv.Itoa(m)
+	}
+
+	var res []string
+	// traverse 0:00 -> 12:00
+	for i := 0; i < 12; i++ {
+		for j := 0; j < 60; j++ {
+			if count(i)+count(j) == num {
+				res = append(res, strconv.Itoa(i)+":"+fmtMinute(j))
+			}
+		}
+	}
+	return res
+}
+
+// 解法二 打表
 var (
 	hour    = []string{"1", "2", "4", "8"}
 	minute  = []string{"01", "02", "04", "08", "16", "32"}
@@ -88,38 +125,3 @@ func findReadBinaryWatchHour(target, index int, c []int, res *[]string) {
 		c = c[:len(c)-1]
 	}
 }
-
-func readBinaryWatch(num int) []string {
-	memo := make([]int, 60)
-	// count the number of 1 in a binary number
-	count := func(n int) int {
-		if memo[n] != 0 {
-			return memo[n]
-		}
-		originN, res := n, 0
-		for n != 0 {
-			n = n & (n - 1)
-			res++
-		}
-		memo[originN] = res
-		return res
-	}
-	// fmtMinute format minute 0:1 -> 0:01
-	fmtMinute := func(m int) string {
-		if m < 10 {
-			return "0" + strconv.Itoa(m)
-		}
-		return strconv.Itoa(m)
-	}
-
-	var res []string
-	// traverse 0:00 -> 12:00
-	for i := 0; i < 12; i++ {
-		for j := 0; j < 60; j++ {
-			if count(i)+count(j) == num {
-				res = append(res, strconv.Itoa(i)+":"+fmtMinute(j))
-			}
-		}
-	}
-	return res
-}

website/content/ChapterFour/0400~0499/0401.Binary-Watch.md

@@ -51,30 +51,67 @@ import (
 	"strconv"
 )
 
+// 解法一
+func readBinaryWatch(num int) []string {
+	memo := make([]int, 60)
+	// count the number of 1 in a binary number
+	count := func(n int) int {
+		if memo[n] != 0 {
+			return memo[n]
+		}
+		originN, res := n, 0
+		for n != 0 {
+			n = n & (n - 1)
+			res++
+		}
+		memo[originN] = res
+		return res
+	}
+	// fmtMinute format minute 0:1 -> 0:01
+	fmtMinute := func(m int) string {
+		if m < 10 {
+			return "0" + strconv.Itoa(m)
+		}
+		return strconv.Itoa(m)
+	}
+
+	var res []string
+	// traverse 0:00 -> 12:00
+	for i := 0; i < 12; i++ {
+		for j := 0; j < 60; j++ {
+			if count(i)+count(j) == num {
+				res = append(res, strconv.Itoa(i)+":"+fmtMinute(j))
+			}
+		}
+	}
+	return res
+}
+
+// 解法二 打表
 var (
 	hour    = []string{"1", "2", "4", "8"}
 	minute  = []string{"01", "02", "04", "08", "16", "32"}
 	hourMap = map[int][]string{
-		0: []string{"0"},
-		1: []string{"1", "2", "4", "8"},
-		2: []string{"3", "5", "9", "6", "10"},
-		3: []string{"7", "11"},
+		0: {"0"},
+		1: {"1", "2", "4", "8"},
+		2: {"3", "5", "9", "6", "10"},
+		3: {"7", "11"},
 	}
 	minuteMap = map[int][]string{
-		0: []string{"00"},
-		1: []string{"01", "02", "04", "08", "16", "32"},
-		2: []string{"03", "05", "09", "17", "33", "06", "10", "18", "34", "12", "20", "36", "24", "40", "48"},
-		3: []string{"07", "11", "19", "35", "13", "21", "37", "25", "41", "49", "14", "22", "38", "26", "42", "50", "28", "44", "52", "56"},
-		4: []string{"15", "23", "39", "27", "43", "51", "29", "45", "53", "57", "30", "46", "54", "58"},
-		5: []string{"31", "47", "55", "59"},
+		0: {"00"},
+		1: {"01", "02", "04", "08", "16", "32"},
+		2: {"03", "05", "09", "17", "33", "06", "10", "18", "34", "12", "20", "36", "24", "40", "48"},
+		3: {"07", "11", "19", "35", "13", "21", "37", "25", "41", "49", "14", "22", "38", "26", "42", "50", "28", "44", "52", "56"},
+		4: {"15", "23", "39", "27", "43", "51", "29", "45", "53", "57", "30", "46", "54", "58"},
+		5: {"31", "47", "55", "59"},
 	}
 )
 
-func readBinaryWatch(num int) []string {
+func readBinaryWatch1(num int) []string {
+	var res []string
 	if num > 8 {
-		return []string{}
+		return res
 	}
-	res := []string{}
 	for i := 0; i <= num; i++ {
 		for j := 0; j < len(hourMap[i]); j++ {
 			for k := 0; k < len(minuteMap[num-i]); k++ {
@@ -135,6 +172,7 @@ func findReadBinaryWatchHour(target, index int, c []int, res *[]string) {
 	}
 }
 
+
 ```