diff --git a/万维调考试题源码/4-2.c b/万维调考试题源码/4-2.c
index 3485462..10ae444 100644
--- a/万维调考试题源码/4-2.c
+++ b/万维调考试题源码/4-2.c
@@ -31,6 +31,14 @@ void sort(int *p, int n)
 {
     int i, j, temp;
     /**********Program**********/
-    
+    i = 0;
+    j = n-1;
+    while(i < j){
+    	temp = p[i];
+    	p[i] = p[j];
+    	p[j] = temp;
+    	i++;
+    	j--;
+	}
     /********** End **********/
-}
\ No newline at end of file
+}