overlapping intervals

Author: Arjiit

MergeOverlappingIntervals.java

@@ -0,0 +1,88 @@
+//Trapping water
+Class Interval {
+    int id;
+    int s;
+    int e;
+    int t;
+    public Interval(int time, int id, int start, int end) {
+        this.id = id;
+        this.t = time;
+        this.s = start;
+        this.e = end;
+    }
+}
+
+
+public class MergeOverlappingIntervals { 
+  
+    // The main function that takes a set of intervals, merges  
+    // overlapping intervals and prints the result  
+    public static void mergeIntervals(List<List<Integer>> vehicleAssignments, int id)  
+    {  
+        // Test if the given set has at least one interval  
+        if (arr.length <= 0)  
+            return;  
+        Interval[] arr = new Interval[vehicleAssignments.size()];
+        for (int i=0; i<vehicleAssignments.size(); i++) {
+            Interval it = new Interval(vehicleAssignments.get(i).get(0), vehicleAssignments.get(i).get(1), vehicleAssignments.get(i).get(2),vehicleAssignments.get(i).get(3));
+            arr[i] = it;
+        }
+    
+        // Create an empty stack of intervals  
+        Stack<Interval> stack=new Stack<>(); 
+    
+        // sort the intervals in increasing order of start time  
+        Arrays.sort(arr,new Comparator<Interval>(){ 
+            public int compare(Interval i1,Interval i2) 
+            { 
+                return i1.s-i2.s; 
+            } 
+        }); 
+    
+        // push the first interval to stack  
+        stack.push(arr[0]);  
+    
+        // Start from the next interval and merge if necessary  
+        for (int i = 1 ; i < arr.length; i++)  
+        {  
+            // get interval from stack top  
+            Interval top = stack.peek();  
+    
+            // if current interval is not overlapping with stack top,  
+            // push it to the stack  
+            if (top.e < arr[i].s)  
+                stack.push(arr[i]);  
+    
+            // Otherwise update the ending time of top if ending of current  
+            // interval is more  
+            else if (top.e < arr[i].e)  
+            {  
+                top.e = arr[i].e;  
+                stack.pop();  
+                stack.push(top);  
+            }  
+        }  
+    
+        // Print contents of stack  
+        System.out.print("The Merged Intervals are: "); 
+        while (!stack.isEmpty())  
+        {  
+            Interval t = stack.pop(); 
+            if (t.id == id) {
+            System.out.print("["+t.s+","+t.e+"] "); 
+        }
+        }   
+    }   
+  
+    public static void main(String args[]) { 
+        List<List<Integer>> list = asList(
+                             asList(100,3005,660000, 660200),
+                             asList(100,3006,660000, 660200),
+                             asList(100,3007,700000, 700200),
+                             asList(200,3008,660000, 660500)
+                           );
+ 
+        mergeIntervals(list, 100); 
+    } 
+} 
+