hello-algo/codes/java/utils/PrintUtil.java
Yudong Jin a005c6ebd3
Some improvements (#1073)
* Update avatar's link in the landing page

* Bug fixes

* Move assets folder from overrides to docs

* Reduce figures' corner radius

* Update copyright

* Update header image

* Krahets -> krahets

* Update the landing page
2024-02-07 22:21:18 +08:00

118 lines
3 KiB
Java
Executable file

/**
* File: PrintUtil.java
* Created Time: 2022-11-25
* Author: krahets (krahets@163.com)
*/
package utils;
import java.util.*;
class Trunk {
Trunk prev;
String str;
Trunk(Trunk prev, String str) {
this.prev = prev;
this.str = str;
}
};
public class PrintUtil {
/* Print a matrix (Array) */
public static <T> void printMatrix(T[][] matrix) {
System.out.println("[");
for (T[] row : matrix) {
System.out.println(" " + row + ",");
}
System.out.println("]");
}
/* Print a matrix (List) */
public static <T> void printMatrix(List<List<T>> matrix) {
System.out.println("[");
for (List<T> row : matrix) {
System.out.println(" " + row + ",");
}
System.out.println("]");
}
/* Print a linked list */
public static void printLinkedList(ListNode head) {
List<String> list = new ArrayList<>();
while (head != null) {
list.add(String.valueOf(head.val));
head = head.next;
}
System.out.println(String.join(" -> ", list));
}
/**
* The interface of the tree printer
* This tree printer is borrowed from TECHIE DELIGHT
* https://www.techiedelight.com/c-program-print-binary-tree/
*/
public static void printTree(TreeNode root) {
printTree(root, null, false);
}
/* Print a binary tree */
public static void printTree(TreeNode root, Trunk prev, boolean isRight) {
if (root == null) {
return;
}
String prev_str = " ";
Trunk trunk = new Trunk(prev, prev_str);
printTree(root.right, trunk, true);
if (prev == null) {
trunk.str = "———";
} else if (isRight) {
trunk.str = "/———";
prev_str = " |";
} else {
trunk.str = "\\———";
prev.str = prev_str;
}
showTrunks(trunk);
System.out.println(" " + root.val);
if (prev != null) {
prev.str = prev_str;
}
trunk.str = " |";
printTree(root.left, trunk, false);
}
/* Helper function to print branches of the binary tree */
public static void showTrunks(Trunk p) {
if (p == null) {
return;
}
showTrunks(p.prev);
System.out.print(p.str);
}
/* Print a hash map */
public static <K, V> void printHashMap(Map<K, V> map) {
for (Map.Entry<K, V> kv : map.entrySet()) {
System.out.println(kv.getKey() + " -> " + kv.getValue());
}
}
/* Print a heap (PriorityQueue) */
public static void printHeap(Queue<Integer> queue) {
List<Integer> list = new ArrayList<>(queue);
System.out.print("堆的数组表示:");
System.out.println(list);
System.out.println("堆的树状表示:");
TreeNode root = TreeNode.listToTree(list);
printTree(root);
}
}