update

nana1220 · Oct 7, 2014 · 92edcff · 92edcff
1 parent 52cd1a1
commit 92edcff
Showing 1 changed file with 17 additions and 0 deletions.
diff --git a/java/src/BinaryPow.java b/java/src/BinaryPow.java
@@ -0,0 +1,17 @@
+public class BinaryPow {
+
+	public static int pow(int x, int n, int mod) {
+		int res = 1;
+		for (long p = x; n > 0; n >>= 1, p = (p * p) % mod) {
+			if ((n & 1) != 0) {
+				res = (int) (res * p % mod);
+			}
+		}
+		return res;
+	}
+
+	// usage example
+	public static void main(String[] args) {
+		System.out.println(8 == pow(2, 3, 100));
+	}
+}