Adding to Swap variables for all CPP,Python, and Java

README.md

@@ -99,7 +99,10 @@ Given two integers, write a function to sum the numbers without using any arithm
 * [Reverse Stack](http://www.byte-by-byte.com/reversestack/)  
 Given a stack, reverse the items without creating any additional data structures.
 
-* [Swap Variables](http://www.byte-by-byte.com/swapvariables/)  
+* [Swap Variables](http://www.byte-by-byte.com/swapvariables/)
+([C++](https://github.com/samgh/Byte-by-Byte-Solutions/blob/master/cpp/SwapVariables.cpp))
+([Java](https://github.com/samgh/Byte-by-Byte-Solutions/blob/master/java/SwapVariables.java))
+([Python](https://github.com/samgh/Byte-by-Byte-Solutions/blob/master/python/SwapVariables.py))<br>
 Given two integers, write a function that swaps them without using any temporary variables.
 
 * [Matrix Search](http://www.byte-by-byte.com/matrixsearch/)  

cpp/SwapVariables.cpp

@@ -0,0 +1,74 @@
+/*
+*   Title: Swap Variables
+*
+*   Given two integers, write a function that swaps them without using any 
+*   temporary variables.
+*
+*   Execution: g++ SwapVariables.cpp -o SwapVariables
+*
+*   For more details, check out http://www.byte-by-byte.com/swapvariables
+*/
+
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+vector<int> swap_1(int x, int y) {
+    vector<int> vars;
+
+    x = x + y;
+    y = x - y;
+    x = x - y;
+
+    vars.push_back(x);
+    vars.push_back(y);
+
+    return vars;
+}
+
+vector<int> swap_2(int x, int y) {
+    vector<int> vars;
+
+    x = x ^ y;
+    y = x ^ y;
+    x = x ^ y;
+
+    vars.push_back(x);
+    vars.push_back(y);
+    return vars;
+}
+
+int main() {
+    vector<int> test_1 = swap_1(1, 2);
+    assert(test_1[0] == 2);
+    assert(test_1[1] == 1);
+    cout << "Swapped (1,2) with (2,1)" << endl;
+
+    vector<int> test_2 = swap_1(5, 5);
+    assert(test_2[0] == 5);
+    assert(test_2[1] == 5);
+    cout << "Swapped (5,5) with (5,5)" << endl;
+
+    vector<int> test_3 = swap_1(-1, 40);
+    assert(test_3[0] == 40);
+    assert(test_3[1] == -1);
+    cout << "Swapped (40,-1) with (-1,40)" << endl;
+
+    vector<int> test_4 = swap_2(1, 2);
+    assert(test_4[0] == 2);
+    assert(test_4[1] == 1);
+    cout << "Swapped (1,2) with (2,1)" << endl;
+
+    vector<int> test_5 = swap_2(5, 5);
+    assert(test_5[0] == 5);
+    assert(test_5[1] == 5);
+    cout << "Swapped (5,5) with (5,5)" << endl;
+
+    vector<int> test_6 = swap_2(-1, 40);
+    assert(test_6[0] == 40);
+    assert(test_6[1] == -1);
+    cout << "Swapped (40,-1) with (-1,40)" << endl;
+
+    return 0;
+}

java/SwapVariables.java

@@ -0,0 +1,62 @@
+/*
+*   Title: Swap Variables
+*
+*   Given two integers, write a function that swaps them without using any temporary variables.
+*
+*   Execution: javac SwapVariables.java && java SwapVariables
+
+*   For more details, check out http://www.byte-by-byte.com/swapvariables
+*/
+
+public class SwapVariables {
+    public static int[] swap_1(int x, int y) {
+        x = x + y;
+        y = x - y;
+        x = x - y;
+
+        int ar[] = new int[2];
+        ar[0] = x;
+        ar[1] = y;
+        return ar; 
+    }
+
+    public static int[] swap_2(int x, int y) {
+        x = x ^ y;
+        y = x ^ y;
+        x = x ^ y;
+
+        int ar[] = new int[2];
+        ar[0] = x;
+        ar[1] = y;
+        return ar;
+    }
+
+    // Sample test cases
+    public static void main(String[] args) {
+        int ar_1[] = swap_1(1, 2);
+        assert ar_1[0] == 2 && ar_1[1] == 1:
+            "Swapped (1,2) with (2,1)";
+
+        int ar_2[] = swap_1(5, 5);
+        assert ar_2[0] == 5 && ar_2[1] == 5:
+            "Swapped (5,5) with (5,5)";
+
+        int ar_3[] = swap_1(-1, 40);
+        assert ar_3[0] == 40 && ar_3[1] == -1:
+            "Swaped(-1,40) with (40,-1)";
+
+        int ar_4[] = swap_2(1, 2);
+        assert ar_4[0] == 2 && ar_4[1] == 1:
+            "Swapped (1,2) with (2,1)";
+
+        int ar_5[] = swap_2(5, 5);
+        assert ar_5[0] == 5 && ar_5[1] == 5:
+            "Swapped (5,5) with (5,5)";
+
+        int ar_6[] = swap_2(-1, 40);
+        assert ar_6[0] == 40 && ar_6[1] == -1:
+            "Swapped(-1,40) with (40,-1)";
+
+        System.out.println("Passed all test cases");
+    }
+}

python/SwapVariables.py

@@ -0,0 +1,56 @@
+"""
+Title: Swap Variables
+
+Given two integers, write a function that swaps them without using any 
+temporary variables.
+
+Execution: python SwapVariables.py
+
+For more details, check out http://www.byte-by-byte.com/swapvariables
+
+"""
+import unittest
+
+
+def swap_1(x: int, y: int):
+    x = x + y
+    y = x - y
+    x = x - y
+    return x, y
+
+
+def swap_2(x: int, y: int):
+    x = x ^ y
+    y = x ^ y
+    x = x ^ y
+    return x, y
+
+
+class TestSwap(unittest.TestCase):
+    def test_swap_1_1_2(self):
+        self.assertEqual(swap_1(1, 2), (2, 1))
+        print("Swapped (1, 2) with (2, 1)")
+
+    def test_swap_1_5_5(self):
+        self.assertEqual(swap_1(5, 5), (5, 5))
+        print("Swapped (5, 5) with (5, 5)")
+
+    def test_swap_1_neg1_40(self):
+        self.assertEqual(swap_1(-1, 40), (40, -1))
+        print("Swapped (-1, 40) with (40, -1)")
+
+    def test_swap_2_1_2(self):
+        self.assertEqual(swap_2(1, 2), (2, 1))
+        print("Swapped (1, 2) with (2, 1)")
+
+    def test_swap_2_5_5(self):
+        self.assertEqual(swap_2(5, 5), (5, 5))
+        print("Swapped (5, 5) with (5, 5)")
+
+    def test_swap_2_neg1_40(self):
+        self.assertEqual(swap_2(-1, 40), (40, -1))
+        print("Swapped (-1, 40) with (40, -1)")
+
+
+if __name__ == '__main__':
+    unittest.main()