feat: cap3 work7 ~ work12

cap3/work10.go

@@ -1 +1,34 @@
 package cap3
+
+// Work10 狼找兔子，返回兔子是否有幸免的机会，有则返回可能的洞穴
+func Work10(m, n int) (bool, []int) {
+	gcd := func(m, n int) int {
+		a, b := m, n
+		if m < n {
+			a, b = n, m
+		}
+
+		r := a % b
+		for r != 0 {
+			a = b
+			b = r
+			r = a % b
+		}
+
+		return b
+	}
+
+	r := gcd(m, n)
+	if r == 1 {
+		return false, nil
+	}
+
+	safeHoles := make([]int, 0)
+	for i := 0; i < n; i++ {
+		if i%r != 0 {
+			safeHoles = append(safeHoles, i)
+		}
+	}
+
+	return true, safeHoles
+}

cap3/work11.go

@@ -1 +1,13 @@
 package cap3
+
+// Work11 求n!结果中0的数量
+func Work11(n int) int {
+	count := 0
+	for i := 1; i <= n; i++ {
+		for num := i; num%5 == 0; num /= 5 {
+			count++
+		}
+	}
+
+	return count
+}

cap3/work12.go

@@ -1 +1,24 @@
 package cap3
+
+func Work12() []int {
+	size := 52
+	cardStatus := make([]bool, 52)
+	start, count := 2, 0
+	for count <= 104 {
+		for j := start; j < size; j++ {
+			if j%start == 0 {
+				cardStatus[j] = !cardStatus[j]
+				count++
+			}
+		}
+	}
+
+	result := make([]int, 0)
+	for i, faceDown := range cardStatus {
+		if !faceDown {
+			result = append(result, i)
+		}
+	}
+
+	return result
+}

cap3/work13.go

@@ -1 +1,6 @@
 package cap3
+
+//func Work13() map[string]int {
+//    students := []string{"A", "B", "C", "D", "E"}
+//
+//}

cap3/work6.go

@@ -1 +1,96 @@
 package cap3
+
+import (
+	"fmt"
+	"strings"
+)
+
+//
+//func Work6(input string) string {
+//
+//}
+
+var before bool = false
+
+func printString(str string) {
+	temp := ""
+	for i := 0; i < len(str); i++ {
+		if i == 0 {
+			before = false
+		} else {
+			if str[i-1] == '*' || str[i-1] == '/' {
+				before = true
+			} else {
+				before = false
+			}
+		}
+		if str[i] == '(' {
+			temp = getString(str[i:])
+			if i == 0 {
+				str = temp
+			} else {
+				str = str[:i] + temp
+			}
+		}
+	}
+	fmt.Println(str)
+}
+
+func getString(str string) string {
+	result := str
+	temp := ""
+	i := 0
+	length := 0
+	add := false
+	for i = 1; i < len(str); {
+		if str[i] == '+' || str[i] == '-' {
+			add = true
+		}
+		if str[i] == '(' {
+			temp = getString(str[i:])
+			length = len(temp) + len(str[:i])
+			str = str[:i] + temp
+			if length != len(result) {
+				if i > 1 {
+					i--
+				}
+			} else {
+				i = strings.Index(str, ")") + 1
+			}
+			result = str
+			continue
+		}
+		if str[i] == ')' {
+			break
+		}
+		i++
+	}
+	result = str
+	if before {
+		return result
+	}
+	if !add {
+		if i+1 < len(str) {
+			str = str[1:]
+			temp = str
+			result = str[:i-1] + temp[i:]
+		} else if i+1 == len(str) {
+			str = str[1:]
+			temp = str
+			result = str[:i-1] + temp[i:]
+		}
+	} else {
+		if i+1 < len(str) {
+			if str[i+1] != '*' && str[i+1] != '/' {
+				str = str[1:]
+				temp = str
+				result = str[:i-1] + temp[i:]
+			}
+		} else if i+1 == len(str) {
+			str = str[1:]
+			temp = str
+			result = str[:i-1] + temp[i:]
+		}
+	}
+	return result
+}

cap3/work7.go

@@ -1 +1,18 @@
 package cap3
+
+func Work7(m, n int) int {
+	var ack func(m, n int) int
+	ack = func(m, n int) int {
+		if m == 0 {
+			return n + 1
+		}
+
+		if n == 0 {
+			return ack(m-1, 1)
+		}
+
+		return ack(m-1, ack(m, n-1))
+	}
+
+	return ack(m, n)
+}

cap3/work8.go

@@ -1 +1,12 @@
 package cap3
+
+func Work8(input string) bool {
+	length := len(input)
+	for i := 0; i < length/2; i++ {
+		if input[i] != input[length-1-i] {
+			return false
+		}
+	}
+
+	return true
+}

cap3/work9.go

@@ -1 +1,28 @@
 package cap3
+
+// Work9 蚂蚁爬房，求a~b路线数，动规解法，时间O(n)，空间O(1)
+func Work9(a, b int) int {
+	if a > b {
+		return 0
+	}
+
+	length := b - a
+	if length <= 2 {
+		return 1
+	}
+
+	// 从a开始到后两个房间路线分别有一个和两种路线
+	//a+1:（a->a+1），a+2：（a->a+1->a+2, a->a+2）
+	prev, prev2 := 1, 2
+	step := 0
+	// 前两步已经走过了，所以len-2
+	for i := 0; i < length-2; i++ {
+		step = prev + prev2
+
+		// 上两个变成上一个，上一个变成下一个
+		prev2 = prev
+		prev = step
+	}
+
+	return step
+}

cap3/work_test.go

@@ -53,3 +53,21 @@ func TestWork5(t *testing.T) {
 	matrix = Work5(10)
 	_printMatrix(matrix)
 }
+
+func TestWork9(t *testing.T) {
+	result := Work9(1, 2)
+	println(result)
+	result = Work9(3, 6)
+	println(result)
+}
+
+func TestWork11(t *testing.T) {
+	result := Work11(4)
+	println(result)
+
+	result = Work11(60)
+	println(result)
+
+	result = Work11(1000)
+	println(result)
+}