用C++写一个多级反馈队列调度算法

好的，以下是一个简单的多级反馈队列调度算法的 C 代码实现：

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

#define MAX_PROCESSES 100
#define MAX_QUEUES 5

typedef struct {
    int pid;
    int arrival_time;
    int burst_time;
    int remaining_time;
    int queue_level;
} process_t;

typedef struct {
    int front;
    int rear;
    process_t processes[MAX_PROCESSES];
} queue_t;

void enqueue(queue_t *queue, process_t process) {
    if (queue->rear == MAX_PROCESSES - 1) {
        printf("Error: queue is full\n");
        exit(1);
    }
    queue->rear++;
    queue->processes[queue->rear] = process;
}

process_t dequeue(queue_t *queue) {
    if (queue->front == queue->rear) {
        printf("Error: queue is empty\n");
        exit(1);
    }
    queue->front++;
    return queue->processes[queue->front];
}

int is_empty(queue_t *queue) {
    return queue->front == queue->rear;
}

int main() {
    int num_processes, quantum[MAX_QUEUES], time = 0, i, j;
    process_t processes[MAX_PROCESSES], current_process;
    queue_t queues[MAX_QUEUES];

    // Read input
    printf("Enter number of processes: ");
    scanf("%d", &num_processes);
    for (i = 0; i < num_processes; i++) {
        printf("Enter arrival time and burst time for process %d: ", i + 1);
        scanf("%d %d", &processes[i].arrival_time, &processes[i].burst_time);
        processes[i].remaining_time = processes[i].burst_time;
        processes[i].pid = i + 1;
        processes[i].queue_level = 0;
    }
    printf("Enter time quantum for each queue: ");
    for (i = 0; i < MAX_QUEUES; i++) {
        scanf("%d", &quantum[i]);
    }

    // Initialize queues
    for (i = 0; i < MAX_QUEUES; i++) {
        queues[i].front = 0;
        queues[i].rear = -1;
    }

    // Add processes to first queue
    for (i = 0; i < num_processes; i++) {
        enqueue(&queues[0], processes[i]);
    }

    // Run simulation
    while (1) {
        // Check if all queues are empty
        int all_empty = 1;
        for (i = 0; i < MAX_QUEUES; i++) {
            if (!is_empty(&queues[i])) {
                all_empty = 0;
                break;
            }
        }
        if (all_empty) {
            break;
        }

        // Get next process to run
        for (i = 0; i < MAX_QUEUES; i++) {
            if (!is_empty(&queues[i])) {
                current_process = dequeue(&queues[i]);
                break;
            }
        }

        // Run process for one quantum
        for (j = 0; j < quantum[current_process.queue_level]; j++) {
            current_process.remaining_time--;
            time++;
            if (current_process.remaining_time == 0) {
                printf("Process %d completed at time %d\n", current_process.pid, time);
                break;
            }
        }

        // Add process to next queue if it hasn't completed
        if (current_process.remaining_time > 0) {
            current_process.queue_level++;
            if (current_process.queue_level == MAX_QUEUES) {
                current_process.queue_level--;
            }
            enqueue(&queues[current_process.queue_level], current_process);
        }
    }

    return 0;
}

希望这个代码能够对你有所帮助！