多目标遗传算法 ------ NSGA-II （部分源码解析）辅助变量 双链表操作 list.c

 /* A custom doubly linked list implemenation */

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

 # include "global.h"
 # include "rand.h"

 /* Insert an element X into the list at location specified by NODE */
 void insert (list *node, int x)
 {
     list *temp;
     if (node==NULL)
     {
         printf("\n Error!! asked to enter after a NULL pointer, hence exiting \n");
         exit();
     }
     temp = (list *)malloc(sizeof(list));
     temp->index = x;
     temp->child = node->child;
     temp->parent = node;
     if (node->child != NULL)
     {
         node->child->parent = temp;
     }
     node->child = temp;
     return;
 }

 /* Delete the node NODE from the list */
 list* del (list *node)
 {
     list *temp;
     if (node==NULL)
     {
         printf("\n Error!! asked to delete a NULL pointer, hence exiting \n");
         exit();
     }
     temp = node->parent;
     temp->child = node->child;
     if (temp->child!=NULL)
     {
         temp->child->parent = temp;
     }
     free (node);
     return (temp);
 }

typedef struct lists
{
    int index;
    struct lists *parent;
    struct lists *child;
} list;

list  结构体中有两个指针，可构成双向链表，数值空间存放   索引序号  。

insert  函数

申请一块新的内存空间，放在在 list  指针   指向的空间之后。

del  函数

将  list  指向 的个体空间释放。

以上两个操作在插入，删除操作后都有修改指针操作，保证原有链表 的  上下链接正常。