c++银行家算法

  1 #include <iostream>
  2 #include<string>
  3 #define False 0
  4 #define True 1
  5 
  6 using namespace std;
  7 
  8 
  9 int Avaliable[100] = { 0 };       //系统->拥有资源
 10 int Max[100][100] = { 0 };        //进程->共需要
 11 int Allocation[100][100] = { 0 }; //进程->已得到
 12 int Need[100][100] = { 0 };       //进程->还需要
 13 
 14 int Work[100] = { 0 };            //模拟->系统->拥有资源
 15 //int Request[100] = { 0 };         //进程->请求资源   0.0貌似后来没用到
 16 
 17 
 18 char name[100] = { 0 };           //资源名称。界面使用
 19 
 20 int temp[100] = { 0 };            //存放安全序列
 21 
 22 
 23 int M = 100;                      //进程的最大数为
 24 int N = 100;                      //资源的最大数为
 25 
 26 
 27 
 28 void showdata();                  //显示资源矩阵
 29 int safe();                       //安全性算法
 30 
 31 
 32 
 33 
 34 
 35 int main()//主函数
 36 {
 37     int i, j, number, choice = -1, m, n, flag;
 38     char ming;
 39 
 40     //------------------------------------------------------------->>>>>>>>   【界面】    >>>
 41     cout << "\t*-----------------------------------------------------*" << endl;
 42     cout << "\t||                                                   ||" << endl;
 43     cout << "\t||              银行家算法实现                       ||" << endl;
 44     cout << "\t||                                                   ||" << endl;
 45     cout << "\t||                                    张金棒         ||" << endl;
 46     cout << "\t||                                                   ||" << endl;
 47     cout << "\t||                                  2016.06.29       ||" << endl;
 48     cout << "\t||                                                   ||" << endl;
 49     cout << "\t*-----------------------------------------------------*" << endl;
 50 
 51 
 52 
 53     //------------------------------------------------------------->>>>>>>>   【初始化】    >>>
 54     cout << "请先输入系统可供资源种类的数量：";
 55     cin >> n;
 56     N = n;
 57 
 58     for (i = 0; i < n; i++)
 59     {
 60         cout << "资源" << i + 1 << "的名称：";
 61         cin >> ming;
 62         name[i] = ming;
 63         cout << "资源的数量：";
 64         cin >> number;
 65         Avaliable[i] = number;
 66     }
 67     cout << endl;
 68     cout << "请输入作业的数量";
 69     cin >> m;
 70     M = m;
 71     cout << "请输入各进程的最大需求量（" << m << "*" << n << "矩阵）[Max]:" << endl;
 72     for (i = 0; i < m; i++)
 73         for (j = 0; j < n; j++)
 74             cin >> Max[i][j];
 75     do
 76     {
 77         flag = 0;
 78         cout << "请输入各进程已经申请的资源量（" << m << "*" << n << "矩阵）[Allocation]:" << endl;
 79         for (i = 0; i < m; i++)
 80             for (j = 0; j < n; j++)
 81             {
 82                 cin >> Allocation[i][j];
 83                 if (Allocation[i][j]>Max[i][j]) flag = 1;
 84                 Need[i][j] = Max[i][j] - Allocation[i][j];
 85                 Avaliable[j] = Avaliable[j] - Allocation[i][j];
 86             }
 87         if (flag)
 88             cout << "申请的资源大于最大需求值，请重新输入！\n";
 89     } while (flag);
 90 
 91 
 92 
 93 
 94 
 95     showdata();//显示各种资源
 96 
 97 
 98 
 99     safe();//用银行家算法判定系统是否安全
100     system("pause");
101     return 0;
102 }
103 
104 
105 //------------------------------------------------------------->>>>>>>>   【界面·显示资源矩阵】    >>>
106 void showdata()
107 {
108     int i, j;
109     cout << "系统当前可用资源[Avaliable]:" << endl;
110     for (i = 0; i < N; i++)
111         cout << name[i] << " ";
112     cout << endl;
113     for (j = 0; j < N; j++)
114         cout << Avaliable[j]<<" ";
115     cout << endl;
116     cout << "           Max        Allocation        Need" << endl;
117     cout << "process   ";
118     for (j = 0; j < 3; j++)
119     {
120         for (i = 0; i < N; i++)
121             cout << name[i] << " ";
122         cout << "        ";
123     }
124     cout << endl;
125     for (i = 0; i < M; i++)
126     {
127         cout << " " << i << "        ";
128         for (j = 0; j < N; j++)
129             cout << Max[i][j] << " ";
130         cout << "        ";
131         for (j = 0; j < N; j++)
132             cout << Allocation[i][j] << " ";
133         cout << "        ";
134         for (j = 0; j < N; j++)
135             cout << Need[i][j] << " ";
136         cout << endl;
137     }
138 }
139 //------------------------------------------------------------->>>>>>>>   【银行家算法】    >>>
140 int safe()
141 {
142     int i, k = 0, m, apply, Finish[100] = { 0 };  //apply [应用，使用]    
143     int j;
144     for (i = 0; i < N; i++)
145     {
146         Work[i] = Avaliable[i];
147     }
148     for (i = 0; i < M; i++)//------------------------------------->>>>>>>>>>选定进程  i   
149     {
150         apply = 0;
151         for (j = 0; j < N; j++)//--------------------------------->>>>>>>>>>选定资源  j
152         {
153             if (Finish[i] == False&&Need[i][j] <= Work[j])//------>>>>>>>>>>第i个进程j类所需资源小于系统拥有的资源
154             {
155                 apply++;   
156                 if (apply == N)//--------------------------------->>>>>>>>>>当i进程各类资源都满足后
157                 {
158                     for (m = 0; m < N; m++)
159                         Work[m] = Work[m] + Allocation[i][m];//--->>>>>>>>>>分配其资源使其运行结束然后回收资源
160                     Finish[i] = True;//--------------------------->>>>>>>>>>i进程执行完毕
161                     temp[k] = i;//-------------------------------->>>>>>>>>>写入进程号到序列中
162                     i = -1;//------------------------------------->>>>>>>>>>检查前面的是否有可满足的
163                     k++;//---------------------------------------->>>>>>>>>>准备好写下一个安全序列项
164                 }
165             }
166         }
167     }
168     for (i = 0; i < M; i++)
169     {
170         if (Finish[i] == False)
171         {
172             cout << "系统不安全" << endl;//不成功 系统不安全
173             return -1;
174         }
175     }
176     cout << "系统是安全的！" << endl;//如果安全，输出成功
177     cout << "分配的序列：";
178     for (i = 0; i < M; i++) //输出运行进程的数组
179     {
180         cout << temp[i];
181         if (i < M - 1) cout << "->";
182     }
183     cout << endl;
184     return 0;
185 }