at - arrival time
bt - burst time
I - idle
for example the user input 3 process
process 1 - at = 5
bt - 5
process 2 - at - 2
bt - 2
process 3 - at - 12
bt - 3
I P2 P1 P3
0 2 4 10 15
this is the logic : smallest time + burst time = sum1
if the next arrival time is less than the sum1 then add the next burst time
but if the next arrival time is greater than the sum1 then subtract the sum1 to the arrival time so you will get the difference1. after that the difference1 must be added to the sum1 then add the burst time. that is the cycle.
what do you think is the appropriate formula with this.