以下代码有什么问题
what is the issue with the below code
下面的邻接表表示
1---2--3-4
2---1--5
3---4--1
4---1--3
5---2--4
打印邻接表后,没有输出。有人可以解释是什么问题。下面的代码是邻接表中无向图的简单实现。
#include<stdio.h>
#include <stdlib.h>
#define maxNode 5
typedef struct Node
{
int vertexNum;
struct Node *next;
} Node;
typedef struct List
{
int n;
struct List *head;
} List;
List *adjlist[maxNode] = { 0 };
void printList ();
void addNode (int source, int destination);
int
main ()
{
/* init our graph nodes */
int i = 1;
for (i; i <= maxNode; i++)
{
adjlist[i] = (List *) malloc (sizeof (List));
adjlist[i]->head = NULL;
}
addNode (1, 2);
addNode (1, 3);
addNode (1, 4);
addNode (2, 1);
addNode (2, 5);
addNode (3, 4);
addNode (3, 1);
addNode (4, 1);
addNode (4, 3);
addNode (5, 2);
addNode (5, 4);
printList ();
return 0;
}
void
addNode (int source, int destination)
{
Node *src = (Node *) malloc (sizeof (Node));
src->vertexNum = source;
Node *dest = (Node *) malloc (sizeof (Node));
dest->vertexNum = destination;
/* now source and destination is an edge */
/* then it should be listed in list */
adjlist[source] = src;
adjlist[source]->head = NULL;
src->next = NULL;
List *tmp = adjlist[source];
while (tmp->head != NULL)
tmp = tmp->head;
tmp->next = dest;
dest->next = NULL;
}
void
printList ()
{
int i = 1;
for (i = 1; i <= maxNode; ++i)
{
Node *p = adjlist[i]->head;
printf ("Adjacency list for vetex %d\n", i);
while (p)
{
printf ("%d ", p->vertexNum);
p = p->next;
}
printf ("\n");
}
}
修复如下
#include <stdio.h>
#include <stdlib.h>
#define maxNode 5+1 //0 : dummy
typedef struct Node {
int vertexNum;
struct Node *next;
} Node;
typedef struct List{
int n;//unused
Node *head;
} List;
List *adjlist[maxNode] = { 0 };
void printList(void);
void addNode(int source, int destination);
int main(void){
int i;
for (i = 1; i <= maxNode; i++){
adjlist[i] = (List *)malloc(sizeof(List));
adjlist[i]->head = NULL;
}
addNode (1, 2);
addNode (1, 3);
addNode (1, 4);
addNode (2, 1);
addNode (2, 5);
addNode (3, 4);
addNode (3, 1);
addNode (4, 1);
addNode (4, 3);
addNode (5, 2);
addNode (5, 4);
printList();
//deallocate
return 0;
}
void addNode(int source, int destination){
if(adjlist[source]->head == NULL){
Node *src = (Node *)malloc(sizeof(Node));
src->vertexNum = source;
src->next = NULL;
adjlist[source]->head = src;
}
Node *dest = (Node *)malloc(sizeof(Node));
dest->vertexNum = destination;
dest->next = NULL;
Node *tmp = adjlist[source]->head;
while (tmp->next != NULL)
tmp = tmp->next;
tmp->next = dest;
}
void printList(void){
int i;
for (i = 1; i <= maxNode; ++i){
Node *p = adjlist[i]->head;
printf ("Adjacency list for vetex %d\n", i);//adjlist[i]->n ?
while (p){
printf ("%d ", p->vertexNum);
p = p->next;
}
printf ("\n");
}
}
下面的邻接表表示
1---2--3-4
2---1--5
3---4--1
4---1--3
5---2--4
打印邻接表后,没有输出。有人可以解释是什么问题。下面的代码是邻接表中无向图的简单实现。
#include<stdio.h>
#include <stdlib.h>
#define maxNode 5
typedef struct Node
{
int vertexNum;
struct Node *next;
} Node;
typedef struct List
{
int n;
struct List *head;
} List;
List *adjlist[maxNode] = { 0 };
void printList ();
void addNode (int source, int destination);
int
main ()
{
/* init our graph nodes */
int i = 1;
for (i; i <= maxNode; i++)
{
adjlist[i] = (List *) malloc (sizeof (List));
adjlist[i]->head = NULL;
}
addNode (1, 2);
addNode (1, 3);
addNode (1, 4);
addNode (2, 1);
addNode (2, 5);
addNode (3, 4);
addNode (3, 1);
addNode (4, 1);
addNode (4, 3);
addNode (5, 2);
addNode (5, 4);
printList ();
return 0;
}
void
addNode (int source, int destination)
{
Node *src = (Node *) malloc (sizeof (Node));
src->vertexNum = source;
Node *dest = (Node *) malloc (sizeof (Node));
dest->vertexNum = destination;
/* now source and destination is an edge */
/* then it should be listed in list */
adjlist[source] = src;
adjlist[source]->head = NULL;
src->next = NULL;
List *tmp = adjlist[source];
while (tmp->head != NULL)
tmp = tmp->head;
tmp->next = dest;
dest->next = NULL;
}
void
printList ()
{
int i = 1;
for (i = 1; i <= maxNode; ++i)
{
Node *p = adjlist[i]->head;
printf ("Adjacency list for vetex %d\n", i);
while (p)
{
printf ("%d ", p->vertexNum);
p = p->next;
}
printf ("\n");
}
}
修复如下
#include <stdio.h>
#include <stdlib.h>
#define maxNode 5+1 //0 : dummy
typedef struct Node {
int vertexNum;
struct Node *next;
} Node;
typedef struct List{
int n;//unused
Node *head;
} List;
List *adjlist[maxNode] = { 0 };
void printList(void);
void addNode(int source, int destination);
int main(void){
int i;
for (i = 1; i <= maxNode; i++){
adjlist[i] = (List *)malloc(sizeof(List));
adjlist[i]->head = NULL;
}
addNode (1, 2);
addNode (1, 3);
addNode (1, 4);
addNode (2, 1);
addNode (2, 5);
addNode (3, 4);
addNode (3, 1);
addNode (4, 1);
addNode (4, 3);
addNode (5, 2);
addNode (5, 4);
printList();
//deallocate
return 0;
}
void addNode(int source, int destination){
if(adjlist[source]->head == NULL){
Node *src = (Node *)malloc(sizeof(Node));
src->vertexNum = source;
src->next = NULL;
adjlist[source]->head = src;
}
Node *dest = (Node *)malloc(sizeof(Node));
dest->vertexNum = destination;
dest->next = NULL;
Node *tmp = adjlist[source]->head;
while (tmp->next != NULL)
tmp = tmp->next;
tmp->next = dest;
}
void printList(void){
int i;
for (i = 1; i <= maxNode; ++i){
Node *p = adjlist[i]->head;
printf ("Adjacency list for vetex %d\n", i);//adjlist[i]->n ?
while (p){
printf ("%d ", p->vertexNum);
p = p->next;
}
printf ("\n");
}
}