Merge pull request algorithm004-05#1078 from TanChungui/master

280-Week 07

Week 7/id_280/LeeCode-191-280.go

@@ -0,0 +1,10 @@
+package main
+
+func hammingWeight(n int) int {
+	sum := 0
+	for n != 0 {
+		sum++
+		n &= n - 1
+	}
+	return sum
+}

Week 7/id_280/LeeCode-56-280.go

@@ -0,0 +1,22 @@
+package main
+
+func merge(intervals [][]int) [][]int {
+	if len(intervals) == 0 {
+		 return [][]int{}
+	 }
+	 merged := make([][]int, 0, len(intervals))
+	 sort.Slice(intervals, func(i, j int) bool {
+		 return intervals[i][0] < intervals[j][0]
+	 })
+	 current := intervals[0]
+	 for i := 1; i < len(intervals); i++ {
+		 if intervals[i][0] > current[1] {
+			 merged = append(merged, current)
+			 current = intervals[i]
+		 } else if intervals[i][1] > current[1] {
+			 current[1] = intervals[i][1]
+		 }
+	 }
+	 merged = append(merged, current)
+	 return merged
+ }

Week 7/id_280/LeeCode-912-280.go

@@ -0,0 +1,155 @@
+package main
+
+import ( 
+	"math"
+)
+
+// 快速排序
+func quickSort(array []int, begin int, end int) []int {
+	if end <= begin {
+		return array
+	}
+	array, pivot := partition(array, begin, end)
+
+	array = quickSort(array, begin, pivot - 1) // 标杆左边
+	array = quickSort(array, pivot + 1, end)   // 标杆右边
+
+	return array
+}
+func partition(a []int, begin int, end int) ([]int, int) {
+	// pivot: 标杆位置，counter: 小于pivot的元素的个数
+	pivot, counter := end, begin
+	for i := begin; i < end; i++ {
+		if a[i] < a[pivot] {
+			a[counter], a[i] = a[i], a[counter]
+			counter++
+		}
+	}
+
+	a[pivot],a[counter] = a[counter], a[pivot]
+
+	return a, pivot
+}
+
+// 归并排序 。。。bug 。。。
+func mergeSort2(array []int, left int, right int) []int {
+	if right <= left {
+		return array
+	}
+
+	mid := (left + right) >> 1 // (left + right) / 2  位运算
+
+	array = mergeSort2(array, left, mid)      // 左排序
+	array = mergeSort2(array, mid + 1, right) // 右排序
+
+	array = merge2(array, left, mid, right)
+
+	return array
+}
+func merge2(arr []int, left int, mid int, right int) []int {
+	length := right - left + 1
+	temp := make([]int, length, length) // new int[right - left + 1]; // 中间数组
+	i, j, k := left, mid + 1, 0
+
+	for i <= mid && j <= right {
+		k++
+		if  arr[i] <= arr[j] {
+			i++
+			temp[k] = i
+		} else {
+			j++
+			temp[k] = j
+		}
+	}
+
+	for i <= mid{
+		k++
+		i++
+		temp[k] = arr[i]
+	}
+	for j <= right {
+		k++
+		j++
+		temp[k] = arr[j]
+	}
+
+	for p := 0; p < len(temp); p++ {
+		arr[left + p] = temp[p]
+	}
+	return arr
+}
+// 归并排序 
+func mergeSort(arr []int) []int {
+	length := len(arr)
+	if length < 2 {
+		return arr
+	}
+
+	middle := int(math.Floor(float64(length / 2)))
+
+	left, right :=arr[0: middle],arr[middle:]
+
+	return merge(mergeSort(left), mergeSort(right))
+}
+func merge(left []int, right []int) []int {
+	var result []int
+
+	for len(left) > 0 && len(right) > 0 {
+		if left[0] <= right[0] {
+			result = append(result, left[0])
+			left = left[1:]
+		} else {
+			result = append(result, right[0])
+			right = right[1:]
+		}
+	}
+
+	for len(left) > 0 {
+		result = append(result, left[0])
+		left = left[1:]
+	}
+
+	for len(right) > 0 {
+		result = append(result, right[0])
+		right = right[1:]
+	}
+
+	return result
+}
+
+// 堆排序 ？
+func heapSort(array []int) []int {
+	length := len(array)
+
+	if len(array) == 0 { return array }
+
+	for i := length / 2 - 1; i >= 0; i-- {
+		array = heapify(array, length, i)
+	}
+
+	for i := length - 1; i >= 0; i-- {
+		array[0], array[i] = array[0], array[i]
+
+		array = heapify(array, i, 0)
+	}
+
+	return array
+}
+func heapify(array []int, length int, i int) []int {
+	left, right, largest := 2 * i + 1, 2 * i + 2, i
+
+	if left < length && array[left] > array[largest] {
+		largest = left
+	}
+	if right < length && array[right] > array[largest] {
+		largest = right
+	}
+
+	if largest != i {
+		array[i], array[largest] = array[largest], array[i]
+		array = heapify(array, length, largest)
+	}
+
+	return array
+}
+