feat: ex20 ~ ex32

cap3/common.go

@@ -0,0 +1,21 @@
+package cap3
+
+import "fmt"
+
+func _printMatrix(matrix [][]int) {
+	for _, row := range matrix {
+		for _, val := range row {
+			fmt.Printf("%d\t", val)
+		}
+		fmt.Println()
+	}
+}
+
+func _makeMatrix(size int) [][]int {
+	matrix := make([][]int, size)
+	for i := range matrix {
+		matrix[i] = make([]int, size)
+	}
+
+	return matrix
+}

cap3/ex20.go

@@ -0,0 +1,43 @@
+package cap3
+
+// Ex20 趣味矩阵
+func Ex20(n int) [][]int {
+	matrix := make([][]int, n)
+	for i := 0; i < len(matrix); i++ {
+		matrix[i] = make([]int, n)
+	}
+
+	for i := range n {
+		for j := range n {
+			// 对角线
+			if i == j || i+j == n-1 {
+				matrix[i][j] = 0
+				continue
+			}
+
+			// 左上部分
+			if i+j < n-1 {
+				if i < j {
+					// 上
+					matrix[i][j] = 1
+				} else {
+					// 左
+					matrix[i][j] = 2
+				}
+			}
+
+			// 右下边部分
+			if i+j > n-1 {
+				if i > j {
+					// 下
+					matrix[i][j] = 3
+				} else {
+					// 右
+					matrix[i][j] = 4
+				}
+			}
+		}
+	}
+
+	return matrix
+}

cap3/ex21.go

@@ -0,0 +1,66 @@
+package cap3
+
+// Ex21 螺旋阵
+func Ex21(n int) [][]int {
+	matrix := _makeMatrix(n)
+
+	// 逐层往里填充
+	num := 1
+	for layer := 0; layer < n/2; layer++ {
+		// 方阵左边
+		for i := layer; i < n-layer; i++ {
+			matrix[i][layer] = num
+			num++
+		}
+
+		// 方阵下边
+		for i := layer + 1; i < n-layer; i++ {
+			matrix[n-layer-1][i] = num
+			num++
+		}
+
+		// 方阵右边
+		for i := n - layer - 2; i >= layer; i-- {
+			matrix[i][n-layer-1] = num
+			num++
+		}
+
+		// 方阵上边
+		for i := n - layer - 2; i > layer; i-- {
+			matrix[layer][i] = num
+			num++
+		}
+	}
+
+	// 奇数阶中间位置需要手动设置
+	if n%2 != 0 {
+		matrix[n/2][n/2] = n * n
+	}
+
+	return matrix
+}
+
+func Ex21type2(n int) [][]int {
+	matrix := _makeMatrix(n + 10)
+
+	row, col, t := 0, 0, 1
+
+	for i := 0; i < n*n; {
+		for j := 0; j < 2*n; j++ {
+			i++
+			matrix[row][col] = i
+
+			switch (j + 1) / (n + 1) {
+			case 0:
+				row += t
+			case 1:
+				col += t
+			}
+		}
+
+		n--
+		t = -t
+	}
+
+	return matrix
+}

cap3/ex22.go

@@ -0,0 +1,43 @@
+package cap3
+
+// Ex22 魔方阵，罗伯法
+func Ex22(n int) [][]int {
+	matrix := _makeMatrix(n)
+	if n%2 == 0 {
+		return matrix
+	}
+
+	// 起始位置在第一行的中间
+	i, j := 0, n/2
+
+	for num := 1; num <= n*n; num++ {
+		matrix[i][j] = num // 填充数字
+		num++              // 下一个数字
+		i--                // 向上移动
+		j++                // 向右移动
+
+		// 如果移动后超出了上边界和右边界
+		if i < 0 && j > n-1 {
+			i += 2 // 向下移动两格
+			j--    // 向左移动一格
+		}
+
+		// 如果超出了上边界
+		if i < 0 {
+			i = n - 1 // 移动到最下面一行
+		}
+
+		// 如果超出了右边界
+		if j > n-1 {
+			j = 0 // 移动到最左边一列
+		}
+
+		// 如果当前位置已经填充了数字
+		if matrix[i][j] != 0 {
+			i += 2 // 向下移动两格
+			j--    // 向左移动一格
+		}
+	}
+
+	return matrix
+}

cap3/ex23.go

@@ -0,0 +1,18 @@
+package cap3
+
+type Pair struct {
+	first, second int
+}
+
+func Ex23(nums []int) [][]int {
+	countMap := _makeMatrix(10)
+
+	for _, num1 := range nums {
+		for _, num2 := range nums {
+			countMap[num1][num2]++
+			countMap[num2][num1]++
+		}
+	}
+
+	return countMap
+}

cap3/ex24.go

@@ -0,0 +1,5 @@
+package cap3
+
+func Ex24(n int) int {
+	return 0
+}

cap3/ex25.go

@@ -0,0 +1,20 @@
+package cap3
+
+func Ex25(studentScore [][]int) int {
+	studentCount := 0
+	for _, scores := range studentScore {
+		scoreCount := 0
+		for _, score := range scores {
+			if score >= 90 {
+				scoreCount++
+			}
+
+			if scoreCount > 3 {
+				studentCount++
+				break
+			}
+		}
+	}
+
+	return studentCount
+}

cap3/ex26.go

@@ -0,0 +1,22 @@
+package cap3
+
+func Ex26(n int) []int {
+	lights := make([]bool, n)
+	// 默认值false，实际上意味着第一个人已经把所有灯关了，没必要再操作一遍
+	// 第i个人，从第二个人开始
+	for i := 2; i <= n; i++ {
+		// 编号为i的倍数的灯状态取反
+		for j := 1; i*j <= n; j++ {
+			lights[i*j-1] = !lights[i*j-1]
+		}
+	}
+
+	result := make([]int, 0, n)
+	for light, on := range lights {
+		if on {
+			result = append(result, light+1)
+		}
+	}
+
+	return result
+}

cap3/ex27.go

@@ -0,0 +1,40 @@
+package cap3
+
+type Ex27Condition int
+
+const (
+	Ex27ConditionMin Ex27Condition = iota
+	Ex27ConditionMax
+)
+
+func Ex27(nums []int) (max1, max2, min1, min2 int) {
+	size := len(nums)
+	if size < 3 {
+		return
+	}
+
+	// 最大的乘积
+	maxProd := nums[size-1] * nums[1]
+	max1, max2 = nums[size-1], nums[1]
+
+	// 最小的乘积
+	minProd := nums[size-1] * nums[1]
+	min1, min2 = nums[size-1], nums[1]
+
+	for i := 1; i < size; i++ {
+		first, second := (size+i-1)%size, (i+1)%size
+		// 当前的乘积
+		currentProd := nums[first] * nums[second]
+
+		// 找出最大最小的乘积
+		if currentProd > maxProd {
+			maxProd = currentProd
+			max1, max2 = nums[first], nums[second]
+		} else if currentProd < minProd {
+			minProd = currentProd
+			min1, min2 = nums[first], nums[second]
+		}
+	}
+
+	return max1, max2, min1, min2
+}

cap3/ex28.go

@@ -0,0 +1,20 @@
+package cap3
+
+func Ex28(nums []int) {
+	n := len(nums)
+	for i := 0; i < n-1; i++ {
+		swapped := false
+		for j := 0; j < n-1-i; j++ {
+			if nums[j] < nums[j+1] {
+				tmp := nums[j]
+				nums[j] = nums[j+1]
+				nums[j+1] = tmp
+				swapped = true
+			}
+		}
+
+		if !swapped {
+			break
+		}
+	}
+}

cap3/ex29.go

@@ -0,0 +1,13 @@
+package cap3
+
+func Ex29(nums []int) bool {
+	for _, num1 := range nums {
+		for _, num2 := range nums {
+			if num1 == num2 {
+				return false
+			}
+		}
+	}
+
+	return true
+}

cap3/ex30.go

@@ -0,0 +1,37 @@
+package cap3
+
+import "math"
+
+type Ex30TriangleType int
+
+const (
+	Ex30TriangleTypeNone        Ex30TriangleType = iota // 不是三角形
+	Ex30TriangleTypeNormal      Ex30TriangleType = iota // 普通三角形
+	Ex30TriangleTypeIsosceles   Ex30TriangleType = iota // 等腰三角形
+	Ex30TriangleTypeEquilateral Ex30TriangleType = iota // 等边三角形
+	Ex30TriangleTypeRight       Ex30TriangleType = iota // 直角三角形
+)
+
+func Ex30(nums []float64) Ex30TriangleType {
+	a, b, c := nums[0], nums[1], nums[2]
+
+	if a <= 0 || b <= 0 || c <= 0 || a+b <= c || a+c <= b || b+c <= a {
+		return Ex30TriangleTypeNone
+	}
+
+	if a == b && b == c {
+		return Ex30TriangleTypeEquilateral
+	}
+
+	if a == b || a == c || b == c {
+		return Ex30TriangleTypeIsosceles
+	}
+
+	if math.Pow(a, 2)+math.Pow(b, 2) == math.Pow(c, 2) ||
+		math.Pow(a, 2)+math.Pow(c, 2) == math.Pow(b, 2) ||
+		math.Pow(b, 2)+math.Pow(c, 2) == math.Pow(a, 2) {
+		return Ex30TriangleTypeRight
+	} else {
+		return Ex30TriangleTypeNormal
+	}
+}

cap3/ex31.go

@@ -0,0 +1,34 @@
+package cap3
+
+func Ex31(a, b, c int) int {
+	lcm, maxNum := 0, 0
+	maxNum = max(a, b, c)
+	for i := 2; i <= maxNum; i++ {
+		hasDivisible := true
+		for hasDivisible {
+			hasDivisible = false
+			if a%i == 0 {
+				a = a / i
+				hasDivisible = true
+			}
+
+			if b%i == 0 {
+				b = b / i
+				hasDivisible = true
+			}
+
+			if c%i == 0 {
+				c = c / i
+				hasDivisible = true
+			}
+
+			if hasDivisible {
+				lcm = lcm * i
+			}
+		}
+
+		maxNum = max(a, b, c)
+	}
+
+	return lcm
+}

cap3/ex32.go

@@ -0,0 +1,28 @@
+package cap3
+
+func Ex32() int {
+	for x := 1; x <= 4; x++ {
+		count := 0
+		if x != 1 {
+			count++
+		}
+
+		if x == 3 {
+			count++
+		}
+
+		if x == 4 {
+			count++
+		}
+
+		if x != 4 {
+			count++
+		}
+
+		if count == 3 {
+			return x
+		}
+	}
+
+	return 0
+}

cap3/ex33.go

@@ -0,0 +1,5 @@
+package cap3
+
+func Ex33() {
+
+}

cap3/ex34.go

@@ -0,0 +1 @@
+package cap3

cap3/ex35.go

@@ -0,0 +1 @@
+package cap3

cap3/ex36.go

@@ -0,0 +1 @@
+package cap3

cap3/ex37.go

@@ -0,0 +1 @@
+package cap3

cap3/ex38.go

@@ -0,0 +1 @@
+package cap3

cap3/ex39.go

@@ -0,0 +1 @@
+package cap3

cap3/ex40.go

@@ -0,0 +1 @@
+package cap3

cap3/ex41.go

@@ -0,0 +1 @@
+package cap3

cap3/example_test.go

@@ -215,3 +215,33 @@ func TestEx19(t *testing.T) {
 	fmt.Println(Ex19(10))
 	fmt.Println(Ex19(100))
 }
+
+func TestEx20(t *testing.T) {
+	matrix := Ex20(5)
+	_printMatrix(matrix)
+}
+
+func TestEx21(t *testing.T) {
+	matrix := Ex21(3)
+	_printMatrix(matrix)
+
+	fmt.Println("----------------")
+
+	matrix = Ex21(4)
+	_printMatrix(matrix)
+
+	fmt.Println("================")
+
+	matrix = Ex21type2(3)
+	_printMatrix(matrix)
+
+	fmt.Println("----------------")
+
+	matrix = Ex21type2(4)
+	_printMatrix(matrix)
+}
+
+func TestEx22(t *testing.T) {
+	m := Ex22(3)
+	_printMatrix(m)
+}

cap3/genfile.sh

@@ -0,0 +1,5 @@
+# shellcheck disable=SC2006
+for count in `seq 20 41`
+do
+   echo 'package cap3' >> ex$count.go
+done

cap3/work10.go

@@ -0,0 +1 @@
+package cap3

cap3/work11.go

@@ -0,0 +1 @@
+package cap3

cap3/work12.go

@@ -0,0 +1 @@
+package cap3

cap3/work13.go

@@ -0,0 +1 @@
+package cap3

cap3/work14.go

@@ -0,0 +1 @@
+package cap3

cap3/work15.go

@@ -0,0 +1 @@
+package cap3

cap3/work16.go

@@ -0,0 +1 @@
+package cap3

cap3/work17.go

@@ -0,0 +1 @@
+package cap3

cap3/work18.go

@@ -0,0 +1 @@
+package cap3

cap3/work19.go

@@ -0,0 +1 @@
+package cap3

cap3/work20.go

@@ -0,0 +1 @@
+package cap3

cap3/work21.go

@@ -0,0 +1 @@
+package cap3

cap3/work22.go

@@ -0,0 +1 @@
+package cap3

cap3/work23.go

@@ -0,0 +1 @@
+package cap3

cap3/work24.go

@@ -0,0 +1 @@
+package cap3

cap3/work25.go

@@ -0,0 +1 @@
+package cap3

cap3/work26.go

@@ -0,0 +1 @@
+package cap3

cap3/work27.go

@@ -0,0 +1 @@
+package cap3

cap3/work6.go

@@ -0,0 +1 @@
+package cap3

cap3/work7.go

@@ -0,0 +1 @@
+package cap3

cap3/work8.go

@@ -0,0 +1 @@
+package cap3

cap3/work9.go

@@ -0,0 +1 @@
+package cap3

cap3/work_test.go

@@ -14,15 +14,6 @@ func TestWork1(t *testing.T) {
 	fmt.Println()
 }
 
-func _printMatrix(matrix [][]int) {
-    for _, row := range matrix {
-        for _, element := range row {
-            fmt.Printf("%d\t", element)
-        }
-        fmt.Println()
-    }
-}
-
 func TestWork2(t *testing.T) {
 	matrix := Work2([]int{5, 7, 4, 8, 9, 1})
 	_printMatrix(matrix)