pta-数据结构与算法题目集（中文)-4-3 求链式表的表长

函数接口定义：

int Length( List L );

typedef struct LNode *PtrToLNode;
struct LNode {
ElementType Data;
PtrToLNode Next;
};
typedef PtrToLNode List;

裁判测试程序样例：

#include <stdio.h>
#include <stdlib.h>

typedef int ElementType;
typedef struct LNode *PtrToLNode;
struct LNode {
ElementType Data;
PtrToLNode Next;
};
typedef PtrToLNode List;

List Read(); /* 细节在此不表 */

int Length( List L );

int main()
{
List L = Read();
printf("%d\n", Length(L));
return 0;
}

/* 你的代码将被嵌在这里 */

输入样例：

1 3 4 5 2 -1

输出样例：

5

#include <stdio.h>
#include <stdlib.h>

typedef int ElementType;
typedef struct LNode *PtrToLNode;
struct LNode {
ElementType Data;
PtrToLNode Next;
};
typedef PtrToLNode List;

List Read(); /* 细节在此不表 */

int Length( List L );

int main()
{
List L = Read();
printf("%d\n", Length(L));
return 0;
}

List Read(){

int num = 0;
scanf( "%d",&num );
if( -1 == num  ){
return NULL;
}

List list = ( List )malloc( sizeof( struct LNode ) );
List last = list;
list->Data = num;
list->Next = NULL;

scanf( "%d",&num );
while( -1 != num  ){
PtrToLNode node = ( List )malloc( sizeof( struct LNode ) );
node->Data = num;
node->Next = NULL;
last->Next = node;
last = node;
scanf( "%d",&num );
}

return list;
}

int Length( List L ){
PtrToLNode node = L;
int len = 0;
if(  NULL == L  ){

}
while(  NULL != node ){
len++;
node = node->Next;
}

return len;
}