code prefext

testlib/src/main/java/G字符串/A002查找最大的回文子串/MainAlgorithm.java

@@ -11,7 +11,7 @@ import E链表.A001实现一个链表.ListNode;
  */
 public class MainAlgorithm {
   public static void main(String[] args) {
-    String str = "abc3220440223123131abcdefgha101ahgfedcba";
+    String str = "2112";
     String s = getLongtext(str);
     System.out.println(s);
   }

testlib/src/main/java/temp/Test20190805_String.java

+package temp;
+
+/**
+ * Description: <Test20190805_String><br>
+ * Author: mxdl<br>
+ * Date: 2019/8/7<br>
+ * Version: V1.0.0<br>
+ * Update: <br>
+ */
+public class Test20190805_String {
+  // 1.翻转一个整数
+  public static int reversInt(int num) {
+    int temp = 0;
+    while (num != 0) {
+      temp = temp * 10 + num % 10;
+      num = num / 10;
+    }
+    return temp;
+  }
+
+  // 2.查找一个数组中最大的非重复字符串
+  public static String findMaxString(String str) {
+    String reg = "(.)\\1+";
+    String[] split = str.split(reg);
+    String max = "";
+    for (String currstr : split) {
+      if (currstr.length() > max.length()) {
+        max = currstr;
+      }
+    }
+    return max;
+  }
+
+  // 3.查找最大的回文字符串
+  public static String getMaxHuiWen(String str) {
+    int m = str.length();
+    boolean[][] arr = new boolean[m][m];
+    int maxlen = 0;
+    for (int i = 0; i < m; i++) {
+      arr[i][i] = true;
+      maxlen = 1;
+    }
+    String result = "";
+    for (int i = 0; i < str.length() - 1; i++) {
+      if (str.charAt(i) == str.charAt(i + 1)) {
+        arr[i][i + 1] = true;
+        result = str.substring(i, i + 1 + 1);
+        maxlen = 2;
+      }
+    }
+    for (int len = 3; len < str.length(); len++) {
+      for (int i = 0, j; (j = i + len - 1) < str.length(); i++) {
+        if (str.charAt(i) == str.charAt(j)) {
+          arr[i][j] = arr[i + 1][j - 1];
+          if (arr[i][j] && maxlen < len) {
+            result = str.substring(i, j + 1);
+          }
+        } else {
+          arr[i][j] = false;
+        }
+      }
+    }
+    return result;
+  }
+
+  public static String getMaxHuiWen1(String str) {
+    boolean[][] arr = new boolean[str.length()][str.length()];
+    int maxlen = 0;
+    String result = null;
+    for (int i = 0; i < str.length(); i++) {
+      arr[i][i] = true;
+    }
+    for (int i = 0; i < str.length()-1; i++) {
+      if (str.charAt(i) == str.charAt(i + 1)) {
+        maxlen = 2;
+        arr[i][i+1] = true;
+        result = str.substring(i, i + 1 + 1);
+      }
+    }
+    for (int len = 3; len <= str.length(); len++) {
+      for (int i = 0, j; (j = i + len - 1) < str.length(); i++) {
+        if(str.charAt(i) == str.charAt(j)){
+          arr[i][j] = arr[i+1][j-1];
+          if(arr[i][j] && maxlen < len){
+            maxlen = len;
+            result = str.substring(i,j+1);
+          }
+        }else{
+          arr[i][j] = false;
+        }
+      }
+    }
+    return result;
+  }
+
+  public static void main(String[] args) {
+
+    int i = reversInt(25461);
+    System.out.println(i);
+
+    String maxString = findMaxString("11abcdef22asaa789456123");
+    System.out.println(maxString);
+
+    String maxHuiWen = getMaxHuiWen1("12abba2");
+
+    System.out.println("maxHuiWen:" + maxHuiWen);
+  }
+
+}

testlib/src/main/java/temp/Test20190805_TreeNode.java

+package temp;
+
+import sun.reflect.generics.tree.Tree;
+
+/**
+ * Description: <Test20190805_TreeNode><br>
+ * Author: mxdl<br>
+ * Date: 2019/8/7<br>
+ * Version: V1.0.0<br>
+ * Update: <br>
+ */
+public class Test20190805_TreeNode {
+  // 1.二叉树的高
+  public static int getTreeHeight(TreeNode treeNode) {
+    if (treeNode == null) {
+      return 0;
+    }
+    int leftHeight = 1 + getTreeHeight(treeNode.leftNode);
+    int rightHeight = 1 + getTreeHeight(treeNode.rightNdoe);
+
+    return leftHeight > rightHeight ? leftHeight : rightHeight;
+  }
+
+  // 2.求二叉树的节点数
+  public static int getTreeNodeCount(TreeNode treeNode) {
+    if (treeNode == null) {
+      return 0;
+    }
+    return 1 + getTreeNodeCount(treeNode.leftNode) + getTreeNodeCount(treeNode.rightNdoe);
+  }
+
+  // 3.判断两个二叉树是否完全相等
+  public static boolean isTreeNodeSame(TreeNode treeNode1, TreeNode treeNode2) {
+    if (treeNode1 == null && treeNode2 == null) {
+      return true;
+    }
+    if (treeNode1 != null && treeNode2 == null) {
+      return false;
+    }
+    if (treeNode1 == null && treeNode2 != null) {
+      return false;
+    }
+    return treeNode1.val == treeNode2.val && isTreeNodeSame(treeNode1.leftNode, treeNode2.leftNode)
+        && isTreeNodeSame(treeNode1.rightNdoe, treeNode2.rightNdoe);
+  }
+
+  //4.判断一个二叉树是否是对等的二叉树
+  public static boolean isSymTreeNdoe(TreeNode treeNode){
+    if(treeNode == null){
+      return true;
+    }else{
+      return isSymTreeNdoe(treeNode.leftNode,treeNode.rightNdoe);
+    }
+  }
+  public static boolean isSymTreeNdoe(TreeNode leftNode,TreeNode rightNode){
+    if(leftNode == null && rightNode == null){
+      return true;
+    }
+    if(leftNode != null && rightNode == null){
+      return false;
+    }
+    if(leftNode == null && rightNode != null){
+      return false;
+    }
+    return leftNode.val == rightNode.val && isSymTreeNdoe(leftNode.leftNode,rightNode.rightNdoe) && isSymTreeNdoe(leftNode.rightNdoe,rightNode.leftNode);
+  }
+  public static void main(String[] args) {
+    TreeNode treeNode = new TreeNode(0);
+    TreeNode treeNode1 = new TreeNode(1);
+    TreeNode treeNode2 = new TreeNode(1);
+    TreeNode treeNode3 = new TreeNode(2);
+    TreeNode treeNode4 = new TreeNode(3);
+    TreeNode treeNode5 = new TreeNode(3);
+    TreeNode treeNode6 = new TreeNode(2);
+    treeNode.leftNode = treeNode1;
+    treeNode.rightNdoe = treeNode2;
+
+    treeNode1.leftNode = treeNode3;
+    treeNode1.rightNdoe = treeNode4;
+
+    treeNode2.leftNode = treeNode5;
+    treeNode2.rightNdoe = treeNode6;
+    // treeNode1.leftNode = treeNode3;
+
+    int treeHeight = getTreeHeight(treeNode);
+    System.out.println("treeHeight:" + treeHeight);
+
+    int treeNodeCount = getTreeNodeCount(treeNode);
+    System.out.println("treeNodeCount:" + treeNodeCount);
+
+    boolean treeNodeSame = isTreeNodeSame(treeNode, treeNode1);
+    System.out.println("treeNodeSame:" + treeNodeSame);
+
+    boolean symTreeNdoe = isSymTreeNdoe(treeNode);
+    System.out.println("symTreeNdoe:" + symTreeNdoe);
+  }
+}