Solution of Pascal's Triangle

Author: icafe

java/Pascal's Triangle/Solution.java

@@ -0,0 +1,43 @@
+import java.util.ArrayList;
+import java.util.List;
+
+
+/**
+ *
+ * this is solution of Pascal's Triangle
+ *
+ * https://oj.leetcode.com/problems/pascals-triangle/
+ *
+ */
+public class PascalTriangle {
+
+    public List<List<Integer>> generate(int numRows) {
+        List<List<Integer>> result = new ArrayList<>();
+
+        if (numRows <= 0) {
+            return result;
+        }
+
+        for (int m = 1; m <= numRows; m++) {
+            result.add(generateRow(m));
+        }
+        return result;
+    }
+
+    public List<Integer> generateRow(int row) {
+        ArrayList<Integer> last = new ArrayList<>();
+        last.add(1);
+
+        for (int i = 1; i < row; i++) {
+            for (int j = last.size() - 2; j >= 0; j--) {
+                last.set(j + 1, last.get(j) + last.get(j + 1));
+            }
+            last.add(1);
+        }
+        return last;
+    }
+
+    public static void main(String[] args) {
+        System.out.println(new PascalTriangle().generate(9));
+    }
+}