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

/*********************************************************************
* 文件名称： // bank_alloc.cpp
* 文件标识： // 
* 内容摘要： //操作系统银行家算法
* 其它说明： //
* 当前版本： // v1.0
* 作    者： //pipi
* 完成日期： // 2011年12月6日
**********************************************************************/
typedef struct  banker
{
    int alloc;
    int need;
    int state; // 0 分配 1释放
    struct banker *next;
}banker_ST,*lpbanker_ST;


void CreateLoopLink(lpbanker_ST head,int alloc_arry[],int need_arry[])
{
    
    lpbanker_ST p = head;
    
    for(int i=0;i<3;i++)
    {
        lpbanker_ST  new_node =  (lpbanker_ST)malloc(sizeof(banker_ST));
        new_node->alloc =  alloc_arry[i];
        new_node->need  =  need_arry[i];
        new_node->state = 0;
        p->next = new_node;
        p = new_node;
    }
    p->next = head->next;
}


void request_now (lpbanker_ST head,int requste)
{
    lpbanker_ST  travel = head;      
    int i = 0;
    
    travel = travel->next;
    
    while((travel->state==0))
    {
        printf("第%d次:",++i);
        if((requste>=travel->need) && (0==travel->state))
        {
            
            printf("  alloc_%d  nedd_%d",travel->alloc,travel->need);
            requste += (travel->alloc+travel->need);
            printf("  requste =%d\n",requste);
            //释放本节点
            travel->state =1;
        }
        else
        {
            printf("不满足回收条件\n");
        }
        travel = travel->next;
    }    
}

int main()
{

    int  alloc_arry[] = {4,7,6};
    int  need_arry [] = {3,5,1};
    
    lpbanker_ST   head = (lpbanker_ST)malloc(sizeof(banker_ST));
    head->alloc = 0;
    head->need = 0;
    lpbanker_ST free_node;
    
    CreateLoopLink(head,alloc_arry,need_arry);
    request_now(head,1);
    
    while(free_node)
    { 
        free_node  = head;
        head =head->next;
        free(free_node);
        free_node = NULL;
    } 
    return 0;
}