diff --git a/12 b/12
new file mode 100644
index 0000000..4c9ffe2
--- /dev/null
+++ b/12
@@ -0,0 +1,47 @@
+
+import java.util.Scanner;
+
+public class Main {
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+
+        System.out.println("请输入数字: ");
+        double num1 = scanner.nextDouble();
+
+        System.out.println("请输入操作符 (+, -, *, /, %): ");
+        char operator = scanner.next().charAt(0);
+
+        System.out.println("请输入数字: ");
+        double num2 = scanner.nextDouble();
+
+        double result = 0;
+
+        switch (operator) {
+            case '+':
+                result = num1 + num2;
+                break;
+            case '-':
+                result = num1 - num2;
+                break;
+            case '*':
+                result = num1 * num2;
+                break;
+            case '/':
+                if (num2 != 0) {
+                    result = num1 / num2;
+                } else {
+                    System.out.println("错误！除数不能为零。");
+                    return;
+                }
+                break;
+            case '%':
+                result = num1 % num2;
+                break;
+            default:
+                System.out.println("无效的操作符！");
+                return;
+        }
+
+        System.out.println("计算的结果是: " + result);
+    }
+}