refactor: fix indexed list iteration

Author: alxkm

src/main/java/com/thealgorithms/scheduling/SJFScheduling.java

@@ -2,7 +2,9 @@
 
 import com.thealgorithms.devutils.entities.ProcessDetails;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Comparator;
+import java.util.Iterator;
 import java.util.List;
 
 /**
@@ -31,13 +33,24 @@ public void scheduleProcesses() {
         int size = processes.size();
         int time = 0;
         int executed = 0;
-        int k = 0;
+
+        Iterator<ProcessDetails> processIterator = processes.iterator();
+
+        // This will track the next process to be checked for arrival time
+        ProcessDetails nextProcess = null;
+        if (processIterator.hasNext()) {
+            nextProcess = processIterator.next();
+        }
 
         while (executed < size) {
-            // Load arrived processes into ready queue
-            while (k < size && processes.get(k).getArrivalTime() <= time) {
-                ready.add(processes.get(k));
-                k++;
+            // Load all processes that have arrived by current time
+            while (nextProcess != null && nextProcess.getArrivalTime() <= time) {
+                ready.add(nextProcess);
+                if (processIterator.hasNext()) {
+                    nextProcess = processIterator.next();
+                } else {
+                    nextProcess = null;
+                }
             }
 
             ProcessDetails running = findShortestJob(ready);
@@ -58,7 +71,7 @@ public void scheduleProcesses() {
      * @return returns the process' with the shortest burst time OR NULL if there are no ready
      *     processes
      */
-    private ProcessDetails findShortestJob(List<ProcessDetails> readyProcesses) {
+    private ProcessDetails findShortestJob(Collection<ProcessDetails> readyProcesses) {
         return readyProcesses.stream().min(Comparator.comparingInt(ProcessDetails::getBurstTime)).orElse(null);
     }