用C语言实现RR算法，每个进程由一个进程控制块(PCB)表示，进程控制块包含进程名、到达时间、完成时间、需要运行时间、已用CPU时间、周转时间、带权周转时间、进程状态

以下是用C语言实现RR算法的代码，涉及到进程控制块的定义和使用：

#include <stdio.h>
#define MAX_PROCESSES 10

// 进程状态
typedef enum {
    READY,
    RUNNING,
    FINISHED
} process_state;

// 进程控制块
typedef struct {
    char name[10];      // 进程名
    int arrival_time;   // 到达时间
    int finish_time;    // 完成时间
    int burst_time;     // 需要运行时间
    int used_time;      // 已用CPU时间
    int turnaround_time;// 周转时间
    float weighted_turnaround_time; // 带权周转时间
    process_state state;// 进程状态
} process_control_block;

int main() {
    int i, j, quantum, num_processes, time;
    float avg_turnaround_time = 0.0, avg_weighted_turnaround_time = 0.0;
    process_control_block processes[MAX_PROCESSES];

    // 输入进程数和时间片长度
    printf("Enter the number of processes: ");
    scanf("%d", &num_processes);
    printf("Enter the time quantum: ");
    scanf("%d", &quantum);

    // 输入每个进程的信息
    for(i = 0; i < num_processes; i++) {
        printf("Enter process name, arrival time and burst time: ");
        scanf("%s %d %d", processes[i].name, &processes[i].arrival_time, &processes[i].burst_time);
        processes[i].state = READY;
        processes[i].used_time = 0;
        processes[i].turnaround_time = 0;
        processes[i].weighted_turnaround_time = 0.0;
    }

    // 运行进程
    time = 0;
    while(1) {
        int all_finished = 1;
        for(i = 0; i < num_processes; i++) {
            if(processes[i].state == READY) {
                all_finished = 0;
                if(processes[i].burst_time - processes[i].used_time > quantum) {
                    // 分配时间片
                    time += quantum;
                    processes[i].used_time += quantum;
                } else {
                    // 运行完成
                    time += processes[i].burst_time - processes[i].used_time;
                    processes[i].used_time = processes[i].burst_time;
                    processes[i].finish_time = time;
                    processes[i].turnaround_time = processes[i].finish_time - processes[i].arrival_time;
                    processes[i].weighted_turnaround_time = (float)processes[i].turnaround_time / processes[i].burst_time;
                    processes[i].state = FINISHED;
                }
            }
        }
        if(all_finished) break;
    }

    // 输出每个进程的信息
    printf("\nProcess\tArrival Time\tBurst Time\tFinish Time\tTurnaround Time\tWeighted Turnaround Time\n");
    for(i = 0; i < num_processes; i++) {
        printf("%s\t%d\t\t%d\t\t%d\t\t%d\t\t%.2f\n", processes[i].name, processes[i].arrival_time, processes[i].burst_time, processes[i].finish_time, processes[i].turnaround_time, processes[i].weighted_turnaround_time);
        avg_turnaround_time += processes[i].turnaround_time;
        avg_weighted_turnaround_time += processes[i].weighted_turnaround_time;
    }
    avg_turnaround_time /= num_processes;
    avg_weighted_turnaround_time /= num_processes;
    printf("Average Turnaround Time: %.2f\n", avg_turnaround_time);
    printf("Average Weighted Turnaround Time: %.2f\n", avg_weighted_turnaround_time);

    return 0;
}

该程序通过循环遍历进程列表，对于处于 READY 状态的进程，采用时间片轮转的方式分配 CPU 时间，直到进程运行完成。在运行完成后，计算出进程的周转时间和带权周转时间，并输出每个进程的信息以及平均周转时间和带权周转时间。