Added code for Merge Intervals Problem

Java/MergeIntervals.java

@@ -0,0 +1,55 @@
+class Solution {
+    public int[][] merge(int[][] intervals) {
+
+        int n = intervals.length;
+
+        if(n <= 1){
+            return intervals;
+        }
+
+        // Sort Intervals --> based on start time
+
+        Arrays.sort(intervals, (a, b) -> {
+
+
+
+            if(a[0] != b[0]){
+                return a[0] - b[0];
+            }
+            else{
+               return a[1] - b[1]; 
+            }
+
+        });
+
+        List<int[]> mergedIntervals = new ArrayList<>();
+
+        int [] currInterval = intervals[0];
+
+        for(int i = 1; i < n; i++){
+               if(intervals[i][0] <= currInterval[1]){
+                   // overlapping interval --> update the end time
+
+                   currInterval[1] = Math.max(currInterval[1], intervals[i][1]);
+
+               }
+
+               else{
+                   // non overlapping interval
+
+                   mergedIntervals.add(currInterval);
+                   currInterval = intervals[i];
+
+               }
+
+        }
+
+
+        mergedIntervals.add(currInterval);
+
+        return mergedIntervals.toArray(new int[mergedIntervals.size()][]);
+
+
+
+    }
+}