Competitive_Coding-3

Triangle

@@ -0,0 +1,31 @@
+// TC - O(n2)
+// SC - O(n2)
+
+// Approach: Each row is built using values from the previous row. 
+class Triangle {
+    public List<List<Integer>> generate(int numRows) {
+
+        if(numRows==0){
+            new ArrayList<>();
+        }
+
+        List<List<Integer>> result = new ArrayList<>();
+
+        for(int i=0; i<numRows; i++){
+            List<Integer> list = new ArrayList<>();
+
+            list.add(1);
+
+            for(int j=1; j<i; j++){
+                list.add(result.get(i-1).get(j-1) + result.get(i-1).get(j));
+            }
+            if(i!=0){
+                list.add(1);
+            }            
+
+            result.add(list);
+        }
+
+        return result;
+    }
+}