c++编程实现银行家算法

以下是C++编程实现银行家算法的示例代码：

#include <iostream>
#include <vector>

using namespace std;

// 银行家算法函数
bool isSafe(vector<vector<int>>& max, vector<vector<int>>& allocation, vector<int>& available) {
    int n = max.size(); // 进程数
    int m = max[0].size(); // 资源种类数

    vector<vector<int>> need(n, vector<int>(m)); // 需求矩阵
    vector<bool> finish(n, false); // 完成标记

    // 计算需求矩阵
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            need[i][j] = max[i][j] - allocation[i][j];
        }
    }

    // 模拟分配资源
    vector<int> work = available; // 可用资源
    vector<int> safeSequence; // 安全序列

    int count = 0; // 完成进程数
    while (count < n) {
        bool found = false;
        for (int i = 0; i < n; i++) {
            if (!finish[i]) {
                bool canAllocate = true;
                for (int j = 0; j < m; j++) {
                    if (need[i][j] > work[j]) {
                        canAllocate = false;
                        break;
                    }
                }
                if (canAllocate) {
                    for (int j = 0; j < m; j++) {
                        work[j] += allocation[i][j];
                    }
                    finish[i] = true;
                    safeSequence.push_back(i);
                    count++;
                    found = true;
                }
            }
        }
        if (!found) {
            break;
        }
    }

    // 判断是否存在安全序列
    if (count == n) {
        cout << "存在安全序列：" << endl;
        for (int i = 0; i < n; i++) {
            cout << "P" << safeSequence[i];
            if (i != n - 1) {
                cout << " -> ";
            }
        }
        cout << endl;
        return true;
    } else {
        cout << "不存在安全序列" << endl;
        return false;
    }
}

int main() {
    // 输入实例数据
    vector<vector<int>> max = {{7, 5, 3}, {3, 2, 2}, {9, 0, 2}, {2, 2, 2}, {4, 3, 3}};
    vector<vector<int>> allocation = {{0, 1, 0}, {2, 0, 0}, {3, 0, 2}, {2, 1, 1}, {0, 0, 2}};
    vector<int> available = {3, 3, 2};

    // 调用银行家算法函数
    isSafe(max, allocation, available);

    return 0;
}