1.cpp

在网上找到的银行家算法

#include <stdio.h>
#include <conio.h>
#include <iostream.h>
typedef struct Max1
{
    int m_a;
    int m_b;
    int m_c;
} Max;
typedef struct Allocation1
{
    int a_a;
    int a_b;
    int a_c;
} Allocation;
typedef struct Need1
{
    int n_a;
    int n_b;
    int n_c;
} Need;
struct Available1
{
    int av_a;
    int av_b;
    int av_c;
} q;
struct pr
{
    char name;
    Max max;
    Allocation allocation;
    Need need;
    int finishflag;
} p[5];
char na[5];
//*****************************

void init() //读入
{
    printf("各进程的NEED：\n");
    FILE *fp;
    fp = fopen("1.txt", "r+");
    for (int i = 0; i < 5; i++)
    {

        fscanf(fp, "%c,%d,%d,%d,%d,%d,%d\n", &p[i].name, &p[i].max.m_a,
            &p[i].max.m_b, &p[i].max.m_c, &p[i].allocation.a_a,
            &p[i].allocation.a_b, &p[i].allocation.a_c);
        p[i].need.n_a = p[i].max.m_a - p[i].allocation.a_a;
        p[i].need.n_b = p[i].max.m_b - p[i].allocation.a_b;
        p[i].need.n_c = p[i].max.m_c - p[i].allocation.a_c;

        printf("%c:%d,%d,%d\n", p[i].name, p[i].need.n_a, p[i].need.n_b,
            p[i].need.n_c);


    }
    fclose(fp);
}

//*****************************
int fenpei() //分配
{
    printf("Available:\n");
    printf("%d,%d,%d\n", q.av_a, q.av_b, q.av_c);
    int finishcnt = 0, k = 0, count = 0;
    for (int j = 0; j < 5; j++)
    {
        p[j].finishflag = 0;
    }

    while (finishcnt < 5)
    {
        for (int i = 0; i < 5; i++)
        {
            if (p[i].finishflag == 0 && q.av_a >= p[i].need.n_a && q.av_b >=
                p[i].need.n_b && q.av_c >= p[i].need.n_c)
            {
                q.av_a += p[i].allocation.a_a;
                q.av_b += p[i].allocation.a_b;
                q.av_c += p[i].allocation.a_c;
                p[i].finishflag = 1;
                finishcnt++;
                na[k++] = p[i].name;

                break;
            }

        }
        count++; //禁止循环过多
        if (count > 5)
        {
            return 0;
        }
    }
    return 1;

}

//*****************************

int shq()
{
    int m, i, j, k;
    printf("请输入进程号和请求资源！如：0   2 0 2\n");
    scanf("%d%d%d%d", &m, &i, &j, &k);
    if (i <= p[m].need.n_a && j <= p[m].need.n_b && k <= p[m].need.n_c)
    {
        if (i <= q.av_a && j <= q.av_b && k <= q.av_c)
        {
            p[m].allocation.a_a += i;
            p[m].allocation.a_b += j;
            p[m].allocation.a_c += k;

            p[m].need.n_a = p[m].max.m_a - p[m].allocation.a_a;
            p[m].need.n_b = p[m].max.m_b - p[m].allocation.a_b;
            p[m].need.n_c = p[m].max.m_c - p[m].allocation.a_c;

            printf("各进程的NEED:\n");
            for (int w = 0; w < 5; w++)
            {
                printf("%c:%d,%d,%d\n", p[w].name, p[w].need.n_a, p[w].need.n_b,
                    p[w].need.n_c);
            }
            return 1;
        }
        else
        {
            printf("Request>Available\n让%c等待......\n", p[m].name);
        }
    }
    else
    {
        printf("Request>Need\n让%c等待......\n", p[m].name);
    }
    return 0;

}


//*****************************

void main()
{
    int flag;
    char c;
    cout << "\n\n\n\n\n\n\n\n\n\t           ";
    for (int i = 0; i < 30; i++)
    {
        cout << "*";
    }
    cout << endl << "\t" << "           * 银  行  家  算  法  演  示 *" << endl;
    cout << endl << "\t" << "           *      \001   大汉    \001         *"
        << endl;
    printf("\t           ");
    for (i = 0; i < 30; i++)
    {
        printf("*");
    }
    printf("\n\n\n\n\n");
    getch();
    printf("\t    请确认已经在\"1.txt\"中正确输入各进程的有关信息\n");
    getch();
    init();
    q.av_a = 10;
    q.av_b = 5;
    q.av_c = 7;

    while (flag)
    {
        for (i = 0; i < 5; i++)
        {
            q.av_a -= p[i].allocation.a_a;
            q.av_b -= p[i].allocation.a_b;
            q.av_c -= p[i].allocation.a_c;
        }
        if (fenpei())
        {
            printf("\n这样配置资源是安全的！\001_\001\n");
            printf("其安全序列是：  ");
            for (int k = 0; k < 5; k++)
            {
                printf("-->%c", na[k]);
            }
            printf("\n");
            printf("有进程发出Request请求向量吗？？？(Enter y or Y)\n");
            c = getch();
            if (c == 'y' || c == 'Y')
            {
                if (shq())
                {
                    continue;
                }
                else
                {
                    break;
                }
            }
            else
            {
                flag = 0;
            }

        }
        else
        {
            flag = 0;
            printf("不安全\n");
        }


    }
}