Implementing Non Preemptive SJF - Drwa Gantt Chart and calculate Avergae Waiting Time and Average turn Around Time

#include<stdio.h>

char pName[20][15],c[20];
int bTime[20],aTime[20],tot_pro,Twt,Ttt,Wt[10];
float Awt,Att;

//DISPLAYING THE GANTT CHART
void Gantt_chart()
{
    int i;
    printf("\n\n\t\t\tGANTT CHART\n");
    printf("\n-----------------------------------------------------------\n");
    for(i=1;i<=tot_pro;i++)
        printf("|\t%s\t",pName[i]);
    printf("|\t\n");  
    printf("\n-----------------------------------------------------------\n");
    printf("\n");
    for(i=1;i<=tot_pro;i++)
        printf("%d\t\t%d|",Wt[i],(Wt[i]+bTime[i]));
    printf("\n-----------------------------------------------------------\n");
    printf("\n");
 }

void Calculate()
{
    int i,T;  //T strt from Intial Time & goes to End
    //For the 1st process
    Wt[1]=aTime[1],T=aTime[1];
    for(i=2;i<=tot_pro;i++)
    {
     T+=bTime[i-1];
     if( (T-aTime[i])>=0 )
     {
        Wt[i]=T; 
     }
     else
      {
      T=(aTime[i]);
      Wt[i]=T;
     }
    }
    for(i=1;i<=tot_pro;i++)
    {
        Twt=Twt+(Wt[i]-aTime[i]);
        Ttt=Ttt+((Wt[i]+bTime[i])-aTime[i]);
    }
    Att=(float)Ttt/tot_pro;
    Awt=(float)Twt/tot_pro;
    printf("\n\n Average Turn around time=%3.2f ms ",Att);
    printf("\n\n AverageWaiting Time=%3.2f ms",Awt);
   
}

int main()
{
 int i,j,tmp,flag;
 //----------Take Input---------//
 printf("Enter the Total No of Process: ");
 scanf("%d",&tot_pro);
 
 for(i=1;i<=tot_pro;i++)
 {
  printf("\n\nEnter the Process %d Name :",(i));
  scanf("%s",&pName[i]);
  printf("\nEnter the Burst Time : ");
  scanf("%d",&bTime[i]);
  printf("\nEnter the Arrival Time :");
  scanf("%d",&aTime[i]);
 }
 
 for(i=1;i<tot_pro;i++)
 {
  for(j=i+1;j<=tot_pro;j++)
  {
   flag=0;
   if(aTime[i]>aTime[j])
   {
    flag=1;
   }
   else
   if(aTime[i]==aTime[j])
   {
    if(bTime[i]>bTime[j])
    flag=1;
   }
   
      if(flag)
      {
           tmp=bTime[i];
       bTime[i]=bTime[j];
       bTime[j]=tmp;
       
       tmp=aTime[i];
       aTime[i]=aTime[j];
       aTime[j]=tmp;
    
    strcpy(c,pName[i]);
    strcpy(pName[i],pName[j]);
    strcpy(pName[j],c);
       
      }
  }
 }
 Calculate();
 Gantt_chart();
 
 return 0;
}