adjacent list — 1

using adjacent list to describe undirected graph

#include <iostream>
#include <cstdlib>

using namespace std;

struct list
{
    int val;
    struct list *next;
};

typedef struct list node;
typedef node *link;
struct list head[6];

int main()
{
    link ptr, newnode;
    int data[14][2] = {{1,2},{2,1},{1,5},{5,1},{2,3},{3,2},{2,4},{4,2},
                       {3,4},{4,3},{3,5},{5,3},{4,5},{5,4}};
    cout << "The adjacent list of the graph : \n";
    for(int i = 1; i < 6; i++)
    {
        head[i].val = i;
        head[i].next = NULL;
        cout << "Vertix " << i << " => ";
        ptr = &(head[i]);

        for(int j = 0;  j < 14; j++)
        {
            if(data[j][0] == i)
            {
                newnode = (link)malloc(sizeof(node));
                newnode->val = data[j][1];
                newnode->next = NULL;
                while(ptr != NULL)
                   ptr = ptr->next;
                ptr = newnode;
                cout << "[" << newnode->val << "] ";
            }
        }
        cout << endl;
    }

    system("PAUSE");
    return EXIT_SUCCESS;
}