银行家算法代码c语言版

以下是银行家算法的C语言实现示例：

#include <stdio.h>
#include <stdbool.h>

#define MAX_PROCESS 10
#define MAX_RESOURCE 10

int allocation[MAX_PROCESS][MAX_RESOURCE];
int max[MAX_PROCESS][MAX_RESOURCE];
int need[MAX_PROCESS][MAX_RESOURCE];
int available[MAX_RESOURCE];
bool finish[MAX_PROCESS];

int num_process, num_resource;

void input()
{
    printf("Enter number of processes: ");
    scanf("%d", &num_process);
    printf("Enter number of resources: ");
    scanf("%d", &num_resource);

    printf("Enter allocation matrix:\n");
    for (int i = 0; i < num_process; i++) {
        for (int j = 0; j < num_resource; j++) {
            scanf("%d", &allocation[i][j]);
        }
    }

    printf("Enter max matrix:\n");
    for (int i = 0; i < num_process; i++) {
        for (int j = 0; j < num_resource; j++) {
            scanf("%d", &max[i][j]);
        }
    }

    printf("Enter available resources:\n");
    for (int i = 0; i < num_resource; i++) {
        scanf("%d", &available[i]);
    }
}

void calculate_need()
{
    for (int i = 0; i < num_process; i++) {
        for (int j = 0; j < num_resource; j++) {
            need[i][j] = max[i][j] - allocation[i][j];
        }
    }
}

bool is_safe()
{
    int work[MAX_RESOURCE];
    for (int i = 0; i < num_resource; i++) {
        work[i] = available[i];
    }

    for (int i = 0; i < num_process; i++) {
        finish[i] = false;
    }

    int count = 0;
    while (count < num_process) {
        bool found = false;
        for (int i = 0; i < num_process; i++) {
            if (!finish[i]) {
                bool can_execute = true;
                for (int j = 0; j < num_resource; j++) {
                    if (need[i][j] > work[j]) {
                        can_execute = false;
                        break;
                    }
                }

                if (can_execute) {
                    for (int j = 0; j < num_resource; j++) {
                        work[j] += allocation[i][j];
                    }
                    finish[i] = true;
                    found = true;
                    count++;
                }
            }
        }

        if (!found) {
            return false;
        }
    }

    return true;
}

int main()
{
    input();
    calculate_need();

    if (is_safe()) {
        printf("Safe sequence: ");
        int seq[MAX_PROCESS];
        int k = 0;
        int count = 0;
        while (count < num_process) {
            for (int i = 0; i < num_process; i++) {
                if (!finish[i]) {
                    bool can_execute = true;
                    for (int j = 0; j < num_resource; j++) {
                        if (need[i][j] > available[j]) {
                            can_execute = false;
                            break;
                        }
                    }

                    if (can_execute) {
                        for (int j = 0; j < num_resource; j++) {
                            available[j] += allocation[i][j];
                        }
                        finish[i] = true;
                        seq[k++] = i;
                        count++;
                        break;
                    }
                }
            }
        }

        for (int i = 0; i < num_process; i++) {
            printf("%d ", seq[i]);
        }
        printf("\n");
    } else {
        printf("Unsafe state\n");
    }

    return 0;
}

在这个示例中，我们首先输入了进程数和资源数，然后输入了分配矩阵，最大需求矩阵和可用资源向量。然后我们计算出需要矩阵，并使用银行家算法来检查系统是否处于安全状态。如果系统处于安全状态，我们打印出安全序列。否则，我们打印出不安全状态。