Added 1-n binary generator

Author: mandliya

Diff for: README.md

@@ -6,8 +6,8 @@
 
 | Current Status|     Stats     |
 | :------------: | :----------: |
-| Total Problems | 143 |
-| Current Streak | 7 days |
+| Total Problems | 144 |
+| Current Streak | 8 days |
 | Longest Streak | 91 ( August 17, 2015 - November 15, 2015 ) |
 
 </center>
@@ -144,6 +144,7 @@ Include contains single header implementation of data structures and some algori
 | You are given an integer N. Find the digits in this number that exactly divide N (division that leaves 0 as remainder) and display their count. For N=24, there are 2 digits (2 & 4). Both of these digits exactly divide 24. So our answer is 2. See more details in header comment of the solution file. | [findDigits.cpp](common_ds_algo_problems/findDigits.cpp)|
 | Encrypt and then decrypts a text using Caeser Cipher. | [caeser_cipher.cpp](common_ds_algo_problems/caeser_cipher.cpp)|
 | Encrypt and then decrypts a text using Vigenère cipher. | [vigenere_cipher.cpp](common_ds_algo_problems/vigenere_cipher.cpp)|
+| Generate binary numbers between 1 to N efficiently. | [n_binary.cpp](common_ds_algo_problems/n_binary.cpp)|
 
 ### Math Problems| Problem | Solution |
 | :------------ | :----------: |

Diff for: common_ds_algo_problems/n_binary.cpp

@@ -0,0 +1,33 @@
+/*
+ * Generate numbers between 1 to N, in binary using a data-structure.
+ */
+
+#include <iostream>
+#include <string>
+#include <queue>
+
+void  print_n_binary(int n)
+{
+    std::queue<std::string> q;
+    q.push("1");
+    int i = 1;
+    while (i++ <= n)
+    {
+        // append 0 and 1 to the existing binary string.
+        //
+        q.push(q.front() + "0");
+        q.push(q.front() + "1");
+
+        std::cout << q.front() << std::endl;
+        q.pop();
+    }
+}
+
+int main()
+{
+    int n;
+    std::cout << "Enter number n:";
+    std::cin >> n;
+    print_n_binary(n);
+    return 0;
+}