简单的快速幂

Author: Dev-XYS

Fast-Exponentiation.cpp

@@ -0,0 +1,32 @@
+#include <cstdio>
+
+using namespace std;
+
+long long m;
+
+// Calcutate a ^ b % m;
+long long qpow(long long a, long long b)
+{
+	if (b == 1)
+	{
+		return a;
+	}
+	
+	long long mid = qpow(a, b >> 1);
+	if ((b & 1) == 0)
+	{
+		return mid * mid % m;
+	}
+	else
+	{
+		return mid * mid % m * a % m;
+	}
+}
+
+int main()
+{
+	long long a, b;
+	scanf("%lld%lld%lld", &a, &b, &m);
+	printf("%lld", qpow(a, b));
+	return 0;
+}