Checking for cycles

Question

I would think that this is a pretty straightforward task however I'm running into some difficulties. Basically I'm given a bunch of "processes" and which can be exectuted in parallel provided they aren't dependent on another processes finishing first. I have to calculate the amount of time needed for all processes to be finished.
So for example, given this:
int[] time = {150, 200, 250};
          String[] prec = {"NYN", "NNY", "NNN"};This means, Process 0 takes 150ms, 1 takes 200ms, and 2 takes 250ms.
Process 0 depends on process 1 to finish, Process 1 waits for process 2, and process 2 has no dependencies. So the total time is 600. My code works however for large cases I seem to have trouble checking for cycles even though I think my code to check for cycles works (a cycle example being if process 2 depended on process 0 as well).
import java.util.*;
public class ParallelProgramming
     public int minTime(int[] time, String[] prec)
          //Go through list of processes and calculate the time
          for(Process p:pList)
               current = p;
               if(!p.visited)
                    check = calcTime(p);
               else check = p.time; //don't waste time going through processes I've already seen
               totalTime=Math.max(totalTime,check);
               if(flag)
                    return -1;
          return totalTime;
     public int calcTime(Process p)
          p.visited = true;
          if(p.parallel)//no dependencies
               return p.time;
          else
               int t = p.time;
               int maxTime = 0;
               for(Integer i:p.deps)//deps is list of processes that this process depends on
                    Process next = pList.get(i);
                    int check = 0;
                    if(next.visited)
                         check=next.time;
                    else check = calcTime(next);
                    if(next != current)//checks for a cycle
                         maxTime = Math.max(maxTime, check);
                    else flag = true;
               t+=maxTime;
               p.time = t;
               return (t);
     }

Answer 1

Sure, sorry this is going to take up quite a bit of space:
Attempt 1:
import java.util.*;
public class ParallelProgramming
     ArrayList<Process> pList = new ArrayList<Process>();
     int totalTime = 0;
     Process current;
     boolean flag = false;
     public int minTime(int[] time, String[] prec)
          //Create a list of processes and link up their dependencies
          for(int i=0;i<time.length;i++)
               Process p = new Process(prec,time[i],i);
               for(int c=0;c<prec[i].length();c++)
                    if(prec[i].charAt(c)=='Y')
                         p.parallel=false;
                         p.deps.add(c);
               pList.add(p);
          //Go through list of processes and calculate the time
          for(Process p:pList)
               current = p;
               int check = 0;
               if(!p.visited)
                    check = calcTime(p);
               else check = p.time;
               if(flag)
                    return -1;
               totalTime=Math.max(totalTime,check);
          return totalTime;
     public int calcTime(Process p)
          p.visited = true;
          if(p.parallel)
               return p.time;
          else
               int t = p.time;
               int maxTime = 0;
               for(Integer i:p.deps)//get each dependent process
                    Process next = pList.get(i);
                    int check = 0;
                    if(next.visited)
                         check=next.time;
                    else check = calcTime(next);
                    if(next != current)
                         maxTime = Math.max(maxTime, check);
                    else flag = true;
               t+=maxTime;
               p.time = t;
               return (t);
     class Process //contains schedule,time for this process, and what number process it is
          int time;
          String sch;
          boolean parallel = true;
          boolean visited = false;
          Integer num;
          ArrayList<Integer> deps = new ArrayList<Integer>();
          public Process(String s,int t,int n)
               sch = s;
               time = t;
               num = n;
          public boolean equals(Object o)
               return num==((Process)o).num;
Fails for this set of data (doesn't report a cycle):time is [299, 986, 91, 28, 462, 70, 805, 234, 730, 746, 3, 276, 999, 35, 982, 7, 632, 915, 82, 945, 55, 639, 988, 147, 702, 552, 739, 908, 833, 85, 904, 443, 47, 828, 159, 10, 260, 998, 242, 213, 990, 817, 839, 96, 995, 59 ]
prec is ["NYNNYYNNNYYNNYNYNNYNYNNYNYNNYNNYYNNYNYNYNYYNYY", "NNNNNYNNNNNNNNNNNNYNNNNNNYNNNNNNNNNNNNNYNYYNNN", "NNNYYYNYNYYYNYYYNNYNYNNNYYYYYYNYYNYYYYNYNYYYNY", "NYNNNYNNYYYNYYYYNNNNYNYYNNNNYNYYYNYYYYNYNYYYNN", "NYNNNYNNNNNNNYNNNNNNNNNYNNNNNNNNNNNYNYNYNNYNNN", "NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN", "YNYYYYNYNYNNYYYYYYYNYNYYYYYNYYNYYNYYYYYYYYYNNY", "NYNNYYNNYYYYYYYNNNNNYNYYNYYNYNYYYYYYYYNYNNYNNY", "YYNNYNNNNNYNNYNYNNNNNNYYNYNNYNNYYNNNNNNNNYNNYY", "NYNNYYNNNNYNNYYYNNNNYNYYNYNNYNNYYNNYNYNYNYNNYY", "NYNNYYNNNNNNNYNYNNYNNNYYNYNNNNNNNNNNNYNYNYYNYN", "YYNNYYNNYYYNNYNNNNYNNNYYNYNNYNNNYNNYNYNYNNYNNY", "YYNNYYNNYYYNNYYYNNYNYNYYNNNNYNNYYNNNYYNYNYNNYY", "NNNNNYNNNNNNNNNNNNNNNNNYNYNNNNNNNNNYNYNYNYYNNN", "NYNNYYNNNNYNNYNYNNYNYNYYNYNNNNNNYNNYNYNYNNNNNY", "NNNNYYNNNNNNNNNNNNYNNNYYNYNNNNNNNNNYNYNYNYYNNY", "YYYYYYNYYYYYYNYYNYNNYYNYYYYYYYYYYYYNYYNYNYYYYY", "NYYYNYNYYYYYNYYYNNYNYNYYYYYYYNYNYYYNYYNYNNYYYY", "NNNNNNNNNNNNNNNNNNNNNNNNNYNNNNNNNNNNNNNNNNNNNN", "YYYYYYYYYNYYYYYYYYYNNYYYYYYNYYYNNYYNNYYYYNYNYN", "NYNNYYNNNNYNNYNYNNYNNNYYNYNNNNNNYNNYNYNYNNYNYY", "YNYYYYNYYYNYNYNYNYYNNNYYNYYYYNNNYYYNNYNYYYYYYY", "NYNNNYNNNNNNNNNNNNYNNNNYNYNNNNNNNNNYNYNYNYYNNY", "NNNNNYNNNNNNNNNNNNYNNNNNNNNNNNNNNNNNNNNYNYYNNN", "YYNNYNNYNYYYYYNNNNYNYNNYNNYNYNYYYNYYYYNYNYYYYY", "NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNYNNNYNNNN", "YYNNNYNNNYYNYYNNNNYNYNYYNNNNYNNNYYYNYNNYNYYNYY", "YYNYNYNYYNYNNYYYNNYNNNYYYYNNNNYYYYNYNYNYNYYNYY", "NYNNYNNNNNNNNYYNNNYNYNYYNYNNNNNNNNNNNYNYNYNNYY", "YNNNNYNYYYNNYNYYNNYNYNYYYYYYNNNNYYNYNYNYNYNYYY", "YYNNYNNNYYYNYYYYNNNNYNNYNYNNYNNYYNNNYYNYNYYNYY", "NYNNYYNNNNYNNYYYNNYNYNYYNNNNYNNNYNNYNYNYNYYNNY", "NYNNNNNNNNNNNYNYNNYNNNNYNYNNNNNNNNNYNYNYNYYNNY", "YYNNYYNNYYYYNYYNNNYNYNYYNYNNYNNNNNYYYNNYNYNNYY", "NYNNYYNNYYYYYNNYNNYNNNYYNYNNYNYYYNNNNYNYNYNNYY", "NNNNNYNNNNNNNYNNNNYNNNNYNNNNNNNNNNNNNYNYNYYNNN", "YYNNYNNNYYYYNNYNNNNNNNYYNYNNYNNYYNNNNYNYNYYNYN", "NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN", "NYYYYNNYYYYYYNNYYYYNNYYYYYYNYYYYYYYYYYNYYYYYNY", "NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNYNNNNNNNN", "YNNYYNNYYYYYYYYYNNYNYNNYYNYYNYYYYNYYYYNYNYYYYY", "NNNNNYNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNYNNNNNNNN", "NNNNNYNNNNNNNNNNNNYNNNNNNYNNNNNNNNNNNYNYNNNNNN", "NYNNYYNYNYNYYNYYNNYNYNYYNYYNYNYYYYYNYYNNNNYNNY", "NYNNYYNNNNNNNYNNNNYNNNNYNYNNNNNNNNNYNYNYNYYNNY", "NNNNYYNNNNNNNYNNNNYNNNNYNYNNNNNNNNNYNYNYNYYNNN" ]