roundrobin.c

#include <stdio.h>
int main() {
 int i,x=-1,k[10],m=0,n,t,s=0;
 int a[50],temp,b[50],p[10],bur[10],bur1[10];
 int wat[10],tur[10],ttur=0,twat=0,j=0;
 float awat,atur;
 printf("Enter no. of process : ");
 scanf("%d", &n);
 for(i=0; i<n; i++)  {
 printf("Burst time for process P%d : ", (i+1));
 scanf("%d", &bur[i]);
 bur1[i] = bur[i];
 }
 printf("Enter the time slice (in ms) : ");
 scanf("%d", &t);
 for(i=0; i<n; i++)  {
 b[i] = bur[i] / t;
 if((bur[i]%t) != 0)
 b[i] += 1;
 m += b[i];
 }

 printf("\n\t\tRound Robin Scheduling\n");
 printf("\nGANTT Chart\n");
 for(i=0; i<m; i++)
 printf("--------");
 printf("\n");
 a[0] = 0;
 while(j < m)
 {
 if(x == n-1)
 x = 0;
 else
 x++;
 if(bur[x] >= t)
 {
 bur[x] -= t;
 a[j+1] = a[j] + t; 

 if(b[x] == 1)
 {
 p[s] = x;
 k[s] = a[j+1];
 s++;
 }
 j++;
 b[x] -= 1;
 printf("    P%d    |", x+1);
 }
 else if(bur[x] != 0)
 {
 a[j+1] = a[j] + bur[x];
 bur[x] = 0;
 if(b[x] == 1)
 {
 p[s] = x;
 k[s] = a[j+1];
 s++;
 }
 j++;
 b[x] -= 1;
 printf(" P%d |",x+1);
 }
 }
 printf("\n");
 for(i=0;i<m;i++)
 printf("--------");
 printf("\n");
 for(j=0; j<=m; j++)
 printf("%d\t", a[j]);
 for(i=0; i<n; i++)
 {
 for(j=i+1; j<n; j++)
 {
 if(p[i] > p[j])
 {
 temp = p[i];
 p[i] = p[j];
 p[j] = temp;
 temp = k[i];
 k[i] = k[j];
 k[j] = temp;
 }
 }
 } 

 for(i=0; i<n; i++)
 {
 wat[i] = k[i] - bur1[i];
 tur[i] = k[i];
 }
 for(i=0; i<n; i++)
 {
 ttur += tur[i];
 twat += wat[i];
 }

 printf("\n\n");
 for(i=0; i<30; i++)
 printf("-");
 printf("\nProcess\tBurst\tTrnd\tWait\n");
 for(i=0; i<30; i++)
 printf("-");
 for (i=0; i<n; i++)
 printf("\nP%-4d\t%4d\t%4d\t%4d", p[i]+1, bur1[i],
tur[i],wat[i]);
 printf("\n");
 for(i=0; i<30; i++)
 printf("-");
 awat = (float)twat / n;
 atur = (float)ttur / n;
 printf("\n\nAverage waiting time : %.2f ms", awat);
 printf("\nAverage turn around time : %.2f ms\n", atur);
 return (0);
}