Merge branch 'master' into scheduling

dynamic_programming/armstrong_number.cpp

@@ -1,21 +1,41 @@
 // Program to check whether a number is an armstrong number or not
 #include <iostream>
-
+#include <cmath>
 using std::cin;
 using std::cout;
 
 int main() {
-    int n, k, d, s = 0;
-    cout << "Enter a number:";
+    int n = 0, temp = 0, rem = 0, count = 0, sum = 0;
+    cout << "Enter a number: ";
     cin >> n;
-    k = n;
-    while (k != 0) {
-        d = k % 10;
-        s += d * d * d;
-        k /= 10;
+    
+    temp = n;
+    
+    /* First Count the number of digits
+       in the given number */
+    while(temp != 0) {
+        temp /= 10;
+        count++;
     }
-    if (s == n)
-        cout << n << "is an armstrong number";
-    else
-        cout << n << "is not an armstrong number";
+
+    /* Calaculation for checking of armstrongs number i.e. 
+       in a n digit number sum of the digits raised to a power of n
+       is equal to the original number */
+    
+    temp = n;
+    while(temp!=0) {
+        rem = temp%10;
+        sum += (int) pow(rem,count);
+        temp/=10;
+    }
+    
+
+    if (sum == n) {
+        cout << n << " is an armstrong number";
+    }
+    else {
+        cout << n << " is not an armstrong number";
+    }
+    
+    return 0;
 }