diff --git a/ex1.cpp b/ex1.cpp
index 6c34b1f..32e37aa 100644
--- a/ex1.cpp
+++ b/ex1.cpp
@@ -3,112 +3,125 @@
 #include <stdlib.h>
 #include <time.h>
 
-#define LENGTH 10000
+int LENGTH;
 //数组长度
+bool RANDOM = false;
+//是否随机生成数组
+int MODE = 0;
+//MODE_1: 迭代
+//MODE_2: 递归
 
 #define OUTPUT
 //是否输出
 
-// #define RANDOM
-//随机数
+int *a;
 
-
-#define MODE_1
-//MODE_1: 迭代
-//MODE_2: 递归
-
-
-int a[LENGTH];
-void init()
-{
-   #ifdef RANDOM
-      srand(time(NULL));
-   #endif
-
-   for(int i = 0 ; i < LENGTH ; i++)
-
-   #ifdef RANDOM
-       a[i]=1+rand()%LENGTH;
-   #else
-      a[i]=LENGTH-i;
-   #endif
-}
-
-void swap(int *a,int *b)
+void swap(int *a, int *b)
 {
    int c = *a;
    *a = *b;
    *b = c;
 }
 
-#ifdef MODE_1
-void bobblesort1A(int a[],int n)
+void bobblesort1A(int a[], int n)
 {
    bool sorted = false;
-   A:
-      sorted = true;
-   
-      for(int i = 1 ; i < n ; i++)
-      {
-         if(a[i-1] > a[i])
-         {
-            swap(&a[i-1],&a[i]);
+A:
+   sorted = true;
 
-           sorted=false;
-         }
-         
+   for (int i = 1; i < n; i++)
+   {
+      if (a[i - 1] > a[i])
+      {
+         swap(&a[i - 1], &a[i]);
+
+         sorted = false;
       }
-      n--;
-   if(sorted==false)
+   }
+   n--;
+   if (sorted == false)
       goto A;
 }
 
-#elif defined MODE_2
-void bobblesort1A(int a[],int n)
+void bobblesort1B(int a[], int n)
 {
-   bool sorted = false;
-      sorted = true;
-      
-      for(int i = 1 ; i < n ; i++)
-      {
-         if(a[i-1] > a[i])
-         {
-            swap(&a[i-1],&a[i]);
 
-           sorted=false;
-         }
-         
+   bool sorted = false;
+   sorted = true;
+
+   for (int i = 1; i < n; i++)
+   {
+      if (a[i - 1] > a[i])
+      {
+         swap(&a[i - 1], &a[i]);
+
+         sorted = false;
       }
-      n--;
-   if(n==1)
+   }
+   n--;
+   if (n == 1)
       return;
 
-   bobblesort1A(a,n);
+   bobblesort1B(a, n);
 }
-#endif
 
-int main(){
+void (*bobblesort1C)(int a[], int n);
+
+void init()
+{
+   srand(time(NULL));
+   a = new int[LENGTH];
+
+   for (int i = 0; i < LENGTH; i++)
+      if (RANDOM == true)
+         a[i] = 1 + rand() % LENGTH;
+      else
+         a[i] = LENGTH - i;
+
+   if (MODE == 1)
+      bobblesort1C = bobblesort1A;
+   else if (MODE == 2)
+      bobblesort1C = bobblesort1B;
+}
+
+int main()
+{
+Begin:
+
+   printf("输入数组长度:");
+   scanf("%d", &LENGTH);
+
+   printf("选择模式:1.迭代 2.递归");
+   scanf("%d", &MODE);
+
+   if ((MODE <= 0) || (MODE >= 3))
+   {
+      printf("错误输入\n");
+      goto Begin;
+   }
+
    init();
    clock_t start_t, end_t;
    double total_t;
 
-   #ifdef OUTPUT
+#ifdef OUTPUT
    printf("Before\n");
-   for(int i=0;i<LENGTH;i++)
-      printf("%d \n",a[i]);
-   #endif
+   for (int i = 0; i < LENGTH; i++)
+      printf("%d \n", a[i]);
+#endif
 
    start_t = clock();
-   bobblesort1A(a,LENGTH);
+   bobblesort1C(a, LENGTH);
    end_t = clock();
 
-   #ifdef OUTPUT
+#ifdef OUTPUT
    printf("After\n");
-   for(int i=0;i<LENGTH;i++)
-      printf("%d \n",a[i]);
-   #endif
+   for (int i = 0; i < LENGTH; i++)
+      printf("%d \n", a[i]);
+#endif
 
-   printf("运算时间: %.4f 秒\n",((double)(end_t - start_t) / CLOCKS_PER_SEC));
+   printf("运算时间: %.4f 秒\n", ((double)(end_t - start_t) / CLOCKS_PER_SEC));
    system("pause");
 
+   goto Begin;
 }
\ No newline at end of file