Competitive coding-3 done

Problem1.java

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+// Time Complexity : O(n^2)
+// Space Complexity : O(1)
+// Did this code successfully run on Leetcode : yes
+// Any problem you faced while coding this : no
+
+
+// Your code here along with comments explaining your approach
+
+/**
+ * For any row, the number of elements is same as the current row count.
+ * Setting first and last element to be 1.
+ * For calculating the middle elements, looking at previous row and doing the sum of (i-1, j) and (i-1,j-1) elements.
+ */
+class Solution {
+    public List<List<Integer>> generate(int numRows) {
+        List<List<Integer>> answer = new ArrayList<>();
+
+        for (int i = 0; i < numRows; i++) {
+            List<Integer> currentRow = new ArrayList<>();
+            for (int j = 0; j <= i; j++) {
+                // if first or last element for any row
+                if (j == 0 || j == i) {
+                    currentRow.add(1);
+                }
+                // if any other element (will only be used starting from row number 3)
+                else {
+                    currentRow.add(answer.get(i - 1).get(j) + answer.get(i - 1).get(j - 1));
+                }
+
+            }
+            answer.add(currentRow);
+        }
+
+        return answer;
+    }
+}