diff --git a/4.cpp b/4.cpp
new file mode 100644
index 0000000..2f9eeaf
--- /dev/null
+++ b/4.cpp
@@ -0,0 +1,130 @@
+#include<stdio.h>
+#include<stdlib.h>
+#define list_init_size 100
+#define listincrement 10
+#define ok 1
+
+typedef int elemtype;
+typedef int status;
+
+typedef struct
+{
+    elemtype *elem;
+    int length;
+    int listsize;
+}sqlist;
+
+
+status initlist(sqlist &l)//构造空线性表 
+{
+    l.elem=(elemtype * )malloc(list_init_size*sizeof(elemtype));
+    l.listsize=list_init_size;
+    l.length=0;
+    return ok;
+}
+
+status listlength(sqlist l)//得到元素的个数 
+{
+	return l.length;
+}
+
+int getelem(sqlist l,int i,elemtype &e)//得到数值 
+{
+    if(i<1||i>l.length)
+    {
+        printf("不合法");
+        return 0;
+    }
+    e=l.elem[i-1];
+    return ok;
+}
+
+status listinsert(sqlist &l,int i,elemtype e)//插入 
+{
+    elemtype *p,*q;
+    q=&(l.elem[i-1]);
+    for(p=&(l.elem[l.length-1]);p>=q;--p)
+            *(p+1)=*p;
+    *q=e;
+    ++l.length;
+    return ok;
+}
+
+void listprint(sqlist l)//输出 
+{
+    int i;
+    for(i=0;i<l.length;i++)
+        printf("%d ",l.elem[i]);
+    printf("\n");
+}
+
+void mergelist(sqlist la,sqlist lb,sqlist &lc)
+{
+	int i,j,k,ai,bj;
+	initlist(lc);
+	i=j=1;
+	k=0;
+	la.length=listlength(la);
+	lb.length=listlength(lb);
+	while((i<=la.length)&&(j<=lb.length))
+	{
+		getelem(la,i,ai);
+		getelem(lb,j,bj);
+		if(ai<=bj)
+		{
+			listinsert(lc,++k,ai);
+			++i;
+		}
+		else
+		{
+			listinsert(lc,++k,bj);
+			++j;
+		}
+		}
+		while(i<=la.length)
+		{
+			getelem(la,i++,ai);
+			listinsert(lc,++k,ai);
+		}
+		while(j<=lb.length)
+		{
+			getelem(lb,j++,bj);
+			listinsert(lc,++k,bj);
+		}
+}
+
+
+    int main()
+{
+	sqlist La,Lb,Lc;
+	int i,j;
+	elemtype x;
+	initlist(La);
+	printf("请输入La的长度：   ");
+	scanf("%d",&i);
+	printf("请输入La中的元素：");
+	for(j=1;j<=i;j++)
+	{
+		scanf("%d",&x);
+		listinsert(La,j,x);
+	}
+	printf("输出La中的元素： ");
+	listprint(La);
+	initlist(Lb);
+	printf("\n请输入Lb的长度：   ");
+	scanf("%d",&j);
+	printf("请输入Lb中的元素：");
+	for(i=1;i<=j;i++)
+	{
+		scanf("%d",&x);
+		listinsert(Lb,i,x);
+	}
+	printf("输出Lb中的元素： ");
+	listprint(Lb);
+	mergelist(La,Lb,Lc);
+	printf("\n输出合并后的顺序表Lc:   ");
+	listprint(Lc);
+	return 0;
+	
+}
+