From bf8ece20044eb115e5f12c7fd8b08485225a11f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=99=86=E5=8A=B2=E6=B6=9B?= <rolandlu@tencent.com>
Date: Tue, 28 Dec 2021 16:39:16 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B5=8B=E8=AF=95=E4=B8=8D=E5=90=8C=E6=97=B6?=
 =?UTF-8?q?=E9=97=B4=E5=A4=8D=E6=9D=82=E5=BA=A6=E7=9A=84=E7=A8=8B=E5=BA=8F?=
 =?UTF-8?q?=E8=BF=90=E8=A1=8C=E6=97=B6=E9=97=B4Java=E7=89=88=E6=9C=AC?=
 =?UTF-8?q?=E6=B5=8B=E8=AF=95=E4=BB=A3=E7=A0=81?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 ...��时了，此时的n究竟是多大？.md | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/problems/前序/On的算法居然超时了，此时的n究竟是多大？.md b/problems/前序/On的算法居然超时了，此时的n究竟是多大？.md
index 2019e691..9a56937c 100644
--- a/problems/前序/On的算法居然超时了，此时的n究竟是多大？.md
+++ b/problems/前序/On的算法居然超时了，此时的n究竟是多大？.md
@@ -206,7 +206,62 @@ int main() {
     }
 }
 
+```
 
+
+Java版本
+```Java
+import java.util.Scanner;
+
+public class TimeComplexity {
+    // o(n)
+    public static void function1(long n) {
+        System.out.println("o(n)算法");
+        long k = 0;
+        for (long i = 0; i < n; i++) {
+            k++;
+        }
+    }
+
+    // o(n^2)
+    public static void function2(long n) {
+        System.out.println("o(n^2)算法");
+        long k = 0;
+        for (long i = 0; i < n; i++) {
+            for (long j = 0; j < n; j++) {
+                k++;
+            }
+        }
+    }
+
+    // o(nlogn)
+    public static void function3(long n) {
+        System.out.println("o(nlogn)算法");
+        long k = 0;
+        for (long i = 0; i < n; i++) {
+            for (long j = 1; j < n; j = j * 2) { // 注意这里j=1
+                k++;
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        while(true) {
+            Scanner in = new Scanner(System.in);
+            System.out.print("输入n: ");
+            int n = in.nextInt();
+            long startTime = System.currentTimeMillis();
+
+            function1(n);
+            // function2(n);
+            // function3(n);
+
+            long endTime = System.currentTimeMillis();
+            long costTime = endTime - startTime;
+            System.out.println("算法耗时 == " + costTime + "ms");
+        }
+    }
+}
 ```
 
 # 总结