class04 归并排序

nibnait · Aug 10, 2022 · cfcc2e8 · cfcc2e8
1 parent e585618
commit cfcc2e8
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Showing 16 changed files with 400 additions and 13 deletions.
diff --git a/src/main/java/algorithm_practice/algorithmzuo/a_新手班/class01/Code03_SelectionSort.java b/src/main/java/algorithm_practice/algorithmzuo/a_新手班/class01/Code03_SelectionSort.java
@@ -5,6 +5,7 @@
 import common.util.SysOut;
 import common.util.SysRandom;
 import common.util.SystemUtil;
+import org.junit.Assert;
 import org.junit.Test;
 
 import static common.util.SwapUtil.swap;
@@ -19,12 +20,11 @@ public void testCase() {
         for (int i = 0; i < CommonConstants.TEST_CASE_COUNT; i++) {
             int arr[] = SysRandom.randomArr();
             SysOut.printArray(arr);
-            int[] tmp = CompareUtils.copyArray(arr);
             selectSort(arr);
             SysOut.printArray(arr);
             if (!CompareUtils.isSortAsc(arr)) {
-                System.out.println("！！！有问题：");
-                SysOut.printArray(tmp);
+                SysOut.println("。。。有问题❗️❗️❗️");
+                Assert.assertTrue(false);
             }
 
             SystemUtil.printLiteCuttingLine();

diff --git a/src/main/java/algorithm_practice/algorithmzuo/a_新手班/class01/Code04_BubbleSort.java b/src/main/java/algorithm_practice/algorithmzuo/a_新手班/class01/Code04_BubbleSort.java
@@ -5,6 +5,7 @@
 import common.util.SysOut;
 import common.util.SysRandom;
 import common.util.SystemUtil;
+import org.junit.Assert;
 import org.junit.Test;
 
 import static common.util.SwapUtil.swap;
@@ -19,12 +20,11 @@ public void testCase() {
         for (int i = 0; i < CommonConstants.TEST_CASE_COUNT; i++) {
             int arr[] = SysRandom.randomArr();
             SysOut.printArray(arr);
-            int[] tmp = CompareUtils.copyArray(arr);
             bubbleSort(arr);
             SysOut.printArray(arr);
             if (!CompareUtils.isSortAsc(arr)) {
-                System.out.println("！！！有问题：");
-                SysOut.printArray(tmp);
+                SysOut.println("。。。有问题❗️❗️❗️");
+                Assert.assertTrue(false);
             }
 
             SystemUtil.printLiteCuttingLine();

diff --git a/src/main/java/algorithm_practice/algorithmzuo/a_新手班/class01/Code05_InsertionSort.java b/src/main/java/algorithm_practice/algorithmzuo/a_新手班/class01/Code05_InsertionSort.java
@@ -5,6 +5,7 @@
 import common.util.SysOut;
 import common.util.SysRandom;
 import common.util.SystemUtil;
+import org.junit.Assert;
 import org.junit.Test;
 
 import static common.util.SwapUtil.swap;
@@ -19,13 +20,12 @@ public void testCase() {
         for (int i = 0; i < CommonConstants.TEST_CASE_COUNT; i++) {
             int arr[] = SysRandom.randomArr();
             SysOut.printArray(arr);
-            int[] tmp = CompareUtils.copyArray(arr);
 
             insertSort(arr);
             SysOut.printArray(arr);
             if (!CompareUtils.isSortAsc(arr)) {
-                System.out.println("！！！有问题：");
-                SysOut.printArray(tmp);
+                SysOut.println("。。。有问题❗️❗️❗️");
+                Assert.assertTrue(false);
             }
 
             SystemUtil.printLiteCuttingLine();

diff --git a/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class03/Code01_1_ReverseListNode.java b/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class03/Code01_1_ReverseListNode.java
@@ -19,7 +19,7 @@
 public class Code01_1_ReverseListNode {
 
     @Test
-    public void loolTestCase() {
+    public void loopTestCase() {
         for (int i = 0; i < CommonConstants.TEST_CASE_COUNT_1000; i++) {
             testCase();
         }

diff --git a/.../java/algorithm_practice/algorithmzuo/b_体系学习班/class03/Code01_2_ReverseDoubleListNode.java b/.../java/algorithm_practice/algorithmzuo/b_体系学习班/class03/Code01_2_ReverseDoubleListNode.java
@@ -19,7 +19,7 @@
 public class Code01_2_ReverseDoubleListNode {
 
     @Test
-    public void loolTestCase() {
+    public void loopTestCase() {
         for (int i = 0; i < CommonConstants.TEST_CASE_COUNT; i++) {
             testCase();
         }

diff --git a/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class03/Code02_DeleteGivenValue.java b/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class03/Code02_DeleteGivenValue.java
@@ -13,7 +13,7 @@
 public class Code02_DeleteGivenValue {
 
     @Test
-    public void loolTestCase() {
+    public void loopTestCase() {
         for (int i = 0; i < CommonConstants.TEST_CASE_COUNT_1000; i++) {
             testCase();
         }

diff --git a/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class04/Code01_MergeSort.java b/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class04/Code01_MergeSort.java
@@ -0,0 +1,115 @@
+package algorithm_practice.algorithmzuo.b_体系学习班.class04;
+
+import common.CommonConstants;
+import common.util.CompareUtils;
+import common.util.SysOut;
+import common.util.SysRandom;
+import common.util.SystemUtil;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Created by nibnait on 2022/07/07
+ */
+public class Code01_MergeSort {
+
+    @Test
+    public void testCase() {
+        for (int i = 0; i < CommonConstants.TEST_CASE_COUNT_1000; i++) {
+            int arr[] = SysRandom.randomNaturalNumArr();
+//            int arr[] = SysRandom.randomArr();
+            SysOut.printArray(arr);
+//            recursiveMergeSort(arr);
+            mergeSort(arr);
+            SysOut.printArray(arr);
+            if (!CompareUtils.isSortAsc(arr)) {
+                SysOut.println("。。。有问题❗️❗️❗️");
+                Assert.assertTrue(false);
+            }
+
+            SystemUtil.printLiteCuttingLine();
+        }
+    }
+
+    /**
+     * 归并排序 非递归
+     */
+    private void mergeSort(int[] arr) {
+        if (arr == null || arr.length < 2) {
+            return;
+        }
+
+        int mergeSize = 1;
+        int length = arr.length;
+        while (mergeSize < length) {
+
+            // 按照步长，开始 merge
+            int left = 0;
+            while (left < length) {
+                if (length - left < mergeSize) {
+                    // 此时已经不存在右边了。不需要再merge了
+                    break;
+                }
+
+                int mid = left + mergeSize - 1;
+                int right = mid + Math.min(mergeSize, length - mid - 1);
+
+                merge(arr, left, mid, right);
+                left = right + 1;
+            }
+
+            // 防止 mergeSize * 2 之后，导致 Integer 溢出
+            if (mergeSize > length / 2) {
+                break;
+            }
+            mergeSize <<= 1;
+        }
+
+    }
+
+    /**
+     * 归并排序 递归版
+     */
+    private void recursiveMergeSort(int[] arr) {
+        if (arr == null || arr.length < 2) {
+            return;
+        }
+
+        process(arr, 0, arr.length - 1);
+    }
+
+    private void process(int[] arr, int left, int right) {
+        if (left == right) {
+            return;
+        }
+
+        int mid = (left + right) / 2;
+        process(arr, left, mid);
+        process(arr, mid + 1, right);
+        merge(arr, left, mid, right);
+    }
+
+    private void merge(int[] arr, int left, int mid, int right) {
+        int p1 = left;
+        int p2 = mid + 1;
+
+        int[] help = new int[arr.length];
+        for (int i = left; i <= right; i++) {
+            help[i] = arr[i];
+        }
+
+        int index = left;
+        while (p1 <= mid && p2 <= right) {
+            arr[index++] = help[p1] < help[p2] ? help[p1++] : help[p2++];
+        }
+
+        while (p1 <= mid) {
+            arr[index++] = help[p1++];
+        }
+
+        while (p2 <= right) {
+            arr[index++] = help[p2++];
+        }
+    }
+
+}
diff --git a/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class04/Code02_SmallSum.java b/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class04/Code02_SmallSum.java
@@ -0,0 +1,77 @@
+package algorithm_practice.algorithmzuo.b_体系学习班.class04;
+
+import common.CommonConstants;
+import common.util.SysOut;
+import org.junit.Test;
+
+/**
+ * Created by nibnait on 2022/07/18
+ */
+public class Code02_SmallSum {
+
+    @Test
+    public void loopTestCase() {
+        for (int i = 0; i < CommonConstants.TEST_CASE_COUNT_1000; i++) {
+            testCase();
+        }
+    }
+
+    @Test
+    public void testCase() {
+        int arr[] = new int[]{1,3,4,2,5};
+        int smallSum = mergeSort(arr);
+        SysOut.println(smallSum);
+        SysOut.printArray(arr);
+    }
+
+    private int mergeSort(int[] arr) {
+        if (arr == null || arr.length < 2) {
+            return 0;
+        }
+
+        return process(arr, 0, arr.length - 1);
+    }
+
+    private int process(int[] arr, int left, int right) {
+        if (left == right) {
+            return 0;
+        }
+
+
+        int mid = (left + right) / 2;
+        return process(arr, left, mid)
+                + process(arr, mid + 1, right)
+                + merge(arr, left, mid, right);
+    }
+
+    private int merge(int[] arr, int left, int mid, int right) {
+        int[] help = new int[arr.length];
+        for (int i = left; i <= right; i++) {
+            help[i] = arr[i];
+        }
+
+        int p1 = left;
+        int p2 = mid + 1;
+        int index = left;
+        int smallSum = 0;
+        while (p1 <= mid && p2 <= right) {
+            if (help[p1] < help[p2]) {
+                smallSum += (right - p2 + 1) * arr[p1];
+                arr[index++] = help[p1++];
+            } else {
+                arr[index++] = help[p2++];
+            }
+        }
+
+        while (p1 <= mid) {
+            arr[index++] = help[p1++];
+        }
+
+        while (p2 <= right) {
+            arr[index++] = help[p2++];
+        }
+
+        return smallSum;
+    }
+
+}
diff --git a/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class04/Code03_ReversePair.java b/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class04/Code03_ReversePair.java
@@ -0,0 +1,35 @@
+package algorithm_practice.algorithmzuo.b_体系学习班.class04;
+
+import common.CommonConstants;
+import common.util.SysOut;
+import org.junit.Test;
+
+/**
+ * Created by nibnait on 2022/07/21
+ */
+public class Code03_ReversePair {
+
+    @Test
+    public void loopTestCase() {
+        for (int i = 0; i < CommonConstants.TEST_CASE_COUNT_1000; i++) {
+            testCase();
+        }
+    }
+
+    @Test
+    public void testCase() {
+        int arr[] = new int[]{1,3,4,2,5};
+        int smallSum = mergeSort(arr);
+        SysOut.println(smallSum);
+        SysOut.printArray(arr);
+    }
+
+    private int mergeSort(int[] arr) {
+
+
+
+        return 0;
+    }
+
+
+}
diff --git a/...ain/java/algorithm_practice/algorithmzuo/b_体系学习班/class04/Code04_BiggerThanRightTwice.java b/...ain/java/algorithm_practice/algorithmzuo/b_体系学习班/class04/Code04_BiggerThanRightTwice.java
@@ -0,0 +1,32 @@
+package algorithm_practice.algorithmzuo.b_体系学习班.class04;
+
+import common.CommonConstants;
+import common.util.SysOut;
+import org.junit.Test;
+
+/**
+ * Created by nibnait on 2022/07/21
+ */
+public class Code04_BiggerThanRightTwice {
+
+    @Test
+    public void loopTestCase() {
+        for (int i = 0; i < CommonConstants.TEST_CASE_COUNT_1000; i++) {
+            testCase();
+        }
+    }
+
+    @Test
+    public void testCase() {
+        int arr[] = new int[]{1,3,4,2,5};
+        int smallSum = mergeSort(arr);
+        SysOut.println(smallSum);
+        SysOut.printArray(arr);
+    }
+
+    private int mergeSort(int[] arr) {
+        return 0;
+    }
+
+
+}
diff --git a/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class05/Code01_CountOfRangeSum.java b/src/main/java/algorithm_practice/algorithmzuo/b_体系学习班/class05/Code01_CountOfRangeSum.java
@@ -0,0 +1,33 @@
+package algorithm_practice.algorithmzuo.b_体系学习班.class05;
+
+import common.CommonConstants;
+import org.junit.Test;
+
+/**
+ * Created by nibnait on 2022/07/21
+ */
+public class Code01_CountOfRangeSum {
+
+    @Test
+    public void loopTestCase() {
+        for (int i = 0; i < CommonConstants.TEST_CASE_COUNT_1000; i++) {
+            testCase();
+        }
+    }
+
+    /**
+     * https://leetcode.cn/problems/count-of-range-sum/
+     */
+    @Test
+    public void testCase() {
+
+
+
+    }
+
+    private int countRangeSum(int[] nums, int lower, int upper) {
+
+        return 0;
+    }
+
+}