Regarding logical error

Question

Dear sir,
following is the question of the assignment provided to me from my college.i hav developed the program for the same question. My problem is that i am getting exact o/p as mentioned in the examples provided with question.But my lecturer is saying that it is not providing the exact o/p according to i/p's
int process[] = {
                1, 2, 3, 4, 5
            int arrival[] = {
                0, 6, 8, 9, 12
            int burst[] = {
                6, 5, 3, 1, 2
            }; The expected output should be : {0, 0, 4, 2, 3 }
The waiting time should not be negative.
But my program is providing the o/p {0,4,-3,-1,3}
Please help me for it. Please see me program below the question and guide me what i should do for it.
Question:Write a program to list the waiting time of the processes based on the arrival time and the burst time under non preemptive scheduling. In the Non preemptive Scheduling,the current process keeps the CPU until it releases the CPU by terminating. the operating system never initiates a context switch from a running process to another process.
The Prototype of the function is_
int[] getWaitingList(int[] process,int[] arrival,int[] burst)
where process represents list of processes,arrival represents the arrival time of the processes and burst represents the execution time of the processes.
the function returns the waiting time of the processes based on the arrival and burst time.
Constraints_
the arrival time of the first process should be started with 0, it never contain duplicate, the current process arrival time should be greater than previous process else return{0}.
the burst time should be greater than 0 and less than 10 else return{0}.
Example 1:_
Input
int process[] = {1, 2, 3, 4};
               int arrival[] = {0, 2, 4, 5};
               int burst[] = {7, 4, 1, 4};
Output: The function getWaitingList() returns {0,6,3,7}
Explaination:Process 1 3 2 4
0 7 8 12 16 starting time of process
The waiting time should be : 0,6,3,7
Example 2:_
Input
int process[] = {1, 2, 3};
               int arrival[] = {0, 4, 8};
               int burst[] = {6, 2, 1};
Output: The function getWaitingList() returns {0,2,0}
Example 3:_
Input int process[] = {1, 2, 3, 4};
               int arrival[] = {2, 0, 4, 5};
               int burst[] = {7, 4, 1, 4};
Output: The function getWaitingList() returns {0}

Answer 1

Program for the above Question:_
public class NonPreemptiveScheduling
     public int[] getWaitingList(int[] process, int[] arrival, int[] burst)
        {      int n=process.length;
                int s=arrival[0]+burst[0];int t,i,j;
              if(arrival[0]!=0)
                 return new int[]{0};
                 for(i=0;i<n-1;i++)
                   if(arrival[i+1]>arrival)
else
return new int[]{0};
for(i=0;i<n;i++)
if(burst[i]>0 && burst[i]<10)
else
return new int[]{0};
int[] wait1=new int[n];
int[] wait=new int[n];
int[] tot=new int[n];
int[] ar1=new int[n];
int[] bu1=new int[n];
int[] pro=new int[n];
wait[0]=0;
for(i=0;i<n;i++)
tot[i]=arrival[i]+burst[i];
for(i=0;i<n;i++)
ar1[i]=arrival[i];
for(i=0;i<n;i++)
bu1[i]=burst[i];
for(i=0;i<n;i++)
pro[i]=process[i];
for(i=1;i<n;i++)
for(j=i;j<n;j++)
if(tot[i]>tot[j])
t=tot[j];
tot[j]=tot[i];
tot[i]=t;
t=pro[j];
pro[j]=pro[i];
pro[i]=t;
t=ar1[j];
ar1[j]=ar1[i];
ar1[i]=t;
t=bu1[j];
bu1[j]=bu1[i];
bu1[i]=t;
for(i=1;i<n;i++)
wait[i]=s-ar1[i];
s=s+bu1[i];
for(i=0;i<n;i++)
wait1[pro[i]-1]=wait[i];
          return wait1;
     public static void main(String args[])
          //testcase 1:
          try
               int process[] = {1, 2, 3, 4};
               int arrival[] = {0, 2, 4, 5};
               int burst[] = {7, 4, 1, 4};
               int[] output = new NonPreemptiveScheduling().getWaitingList(process, arrival, burst);
               if(output!=null && output.length>0)
               for (int i = 0; i < output.length; i++)
                    System.out.print(output[i]+", ");
               System.out.println();
          catch (Exception e)
               e.printStackTrace();
          //testcase 2:
          try
               int process[] = {1, 2, 3};
               int arrival[] = {0, 4, 8};
               int burst[] = {6, 2, 1};
               int[] output = new NonPreemptiveScheduling().getWaitingList(process, arrival, burst);
               if(output!=null && output.length>0)
               for (int i = 0; i < output.length; i++)
                    System.out.print(output[i]+", ");
               System.out.println();
          catch (Exception e)
               e.printStackTrace();
          //testcase 3:
          try
               int process[] = {1, 2, 3, 4};
               int arrival[] = {2, 0, 4, 5};
               int burst[] = {7, 4, 1, 4};
               int[] output = new NonPreemptiveScheduling().getWaitingList(process, arrival, burst);
               if(output!=null && output.length>0)
               for (int i = 0; i < output.length; i++)
                    System.out.print(output[i]+", ");
          catch (Exception e)
               e.printStackTrace();