C program for Round Robin Scheduling Policy

#include<stdio.h>

#include<conio.h>

#define MAX 5

void main (){

                clrscr();

                int pname[MAX],brtime[MAX];

                int end[MAX+1],start[MAX];

                int qtm,total=0,rem =0;

                int num = 0, i;

                for(i=0;i<MAX;i++){

                                brtime[i] = 0;

                }

                printf("\t\tRound-Robin SCHEDULING");

                printf("\nEnter the number of processes  (max. 5): ");

                scanf("%d",&num);

                printf("\nEnter the quantum size: ");

                scanf("%d",&qtm);

                for(i=0;i<num;i++){

                                printf("\nEnter process name, burst time: ");

                                scanf("%d %d",&pname[i],&brtime[i]);

                                total= total + brtime[i];

                }

                rem = total;

                printf("\n");

                while(rem!=0){

                                for(i=0;i<num;i++){

                                                if(brtime[i]==0){

                                                                //do nothing

                                                }

                                                else if(brtime[i]>=qtm){

                                                                brtime[i] = brtime[i] - qtm;

                                                                printf("\n%d ->%d",pname[i],qtm);

                                                                rem = rem- qtm;

                                                }

                                                else{

                                                                printf("\n%d ->%d",pname[i],brtime[i]);

                                                                rem= rem - brtime[i];

                                                                brtime[i]=0;

                                                }

                                }

                }

                printf("\n\nTotal Time = %d",total);

                getch();

 }

Sample Output:

                       Round-Robin SCHEDULING

Enter the number of processes (max. 5): 3

Enter the quantum size: 3

Enter process name, burst time: 1     6

Enter process name, burst time: 2     2

Enter process name, burst time: 3     7

1 ->3

2 ->2

3 ->3

1 ->3

3 ->3

3 ->1

Total Time = 15_

©Dixit Bhatta 2013