Add generate nth row of Pascal triangle

Author: rp-code9

README.md

@@ -188,6 +188,9 @@ Princeton Algorithms [Part 1](https://www.coursera.org/learn/algorithms-part1/)
 * GaussElimination : Gauss elimination or Gauss Jordan method to solve system of linear equations [Java](problems/math/GaussElimination.java)
 * Point2D : Data structure to represent point in 2D space [Java](problems/math/Point2D.java)
 * Point3D : Data structure to represent point in 3D space [Java](problems/math/Point3D.java)
+* Generate Nth row of Pascal triangle
+    * Recursive [C++](problems/math/PascalTriangle.cpp)
+    * Iterative [C++](problems/math/PascalTriangle.cpp)
 
 ## Permutation
 * Permutation of objects [Java](problems/queue/Permutation.java)

problems/math/PascalTriangle.cpp

@@ -0,0 +1,71 @@
+// https://www.geeksforgeeks.org/find-the-nth-row-in-pascals-triangle/
+
+#include <iostream>
+#include <vector>
+
+template <typename T>
+void print(std::vector<T>& items)
+{
+    if (items.size() == 0) {
+        return;
+    }
+
+    for (auto item : items) {
+        std::cout << item << " ";
+    }
+    std::cout << "\n";
+}
+
+std::vector<int> generatePascalTriangleRec(int row)
+{
+    std::vector<int> currentRow;
+    currentRow.push_back(1);
+
+    if (row == 0) {
+        return currentRow;
+    }
+
+    std::vector<int> previousRow = generatePascalTriangleRec(row - 1);
+
+    for (int i = 1; i < previousRow.size(); ++i) {
+        currentRow.push_back(previousRow[i - 1] + previousRow[i]);
+    }
+
+    currentRow.push_back(1);
+
+    return currentRow;
+}
+
+std::vector<int> generatePascalTriangleIter(int row)
+{
+    int previous = 1;
+    std::vector<int> currentRow;
+    currentRow.push_back(1);
+
+    for (int i = 1; i <= row; ++i) {
+        int current = previous * (row - i + 1) / i;
+        currentRow.push_back(current);
+        previous = current;
+    }
+    return currentRow;
+}
+
+int main()
+{
+    int n = 10;
+
+    std::cout << "Recursive\n";
+    for (int i = 0; i < n; ++i) {
+        std::cout << "Row " << i << " : ";
+        std::vector<int> numbers = generatePascalTriangleRec(i);
+        print(numbers);
+    }
+
+    std::cout << "===============================\n";
+    std::cout << "Iterative\n";
+    for (int i = 0; i < n; ++i) {
+        std::cout << "Row " << i << " : ";
+        std::vector<int> numbers = generatePascalTriangleIter(i);
+        print(numbers);
+    }
+}