Exponentiation By Squaring.

main.cpp

@@ -1,21 +1,30 @@
 #include <iostream>
+#include <cstdint> // for std::int64_t
+#include <cassert> // for assert
 
-int getValue()
+std::int64_t powint(std::int64_t base, int exp)
 {
-    std::cout << "Enter an integer: ";
+	assert(exp >= 0 && "powint: exp parameter has negative value");
 
-    int x{};
+	std::int64_t result{ 1 };
-    std::cin >> x;
+	while (exp)
-    return x;
+	{
+		if (exp & 1) {
+            std::cout << "a : " << result << "\n";
+            result *= base;
+		}
+		std::cout << "b : " << exp << "\n";
+		exp >>= 1;
+		std::cout << "c : " << base << "\n";
+		base *= base;
+	}
+
+	return result;
 }
 
 int main()
 {
-    int a{ getValue() };
+	std::cout << powint(7, 12); // 7 to the 12th power
-    int b{ getValue() };
-    int c{ getValue() };
 
-    std::cout << a + (b * c); // order of eval doesn't matter now
+	return 0;
-
-    return 0;
 }