permit bigger modular power arguments, long instead of int

Author: TilmanNeumann

src/main/java/de/tilman_neumann/jml/modular/LegendreSymbol.java

@@ -56,16 +56,15 @@ public int EulerFormula(BigInteger a, int p) {
 	}
 
 	/**
-	 * Computes the Legendre symbol L(a|p) via Eulers formula for a, p int.
-	 * p must be an odd prime.
+	 * Computes the Legendre symbol L(a|p) via Eulers formula for <code>a</code> long, <code>p</code> an odd prime int.
 	 * 
 	 * Eulers formula with int p is quite fast, but the Jacobi symbol may be faster.
 	 *
 	 * @param a
 	 * @param p
 	 * @return Legendre symbol L(a|p)
 	 */
-	public int EulerFormula(int a, int p) {
+	public int EulerFormula(long a, int p) {
 		int modPow = mpe.modPow(a, (p-1)>>1, p);
 		return (modPow>1) ? modPow-p : modPow;
 	}

src/main/java/de/tilman_neumann/jml/modular/ModularPower.java

@@ -55,6 +55,17 @@ public int modPow(BigInteger a, long b, int c) {
   		return modPowCore(a.mod(BigInteger.valueOf(c)).longValue(), b, c);
   	}
 
+	/**
+	 * Computes a^b (mod c) for <code>a, b</code> long, <code>c</code> int. Very fast.
+	 * @param a
+	 * @param b
+	 * @param c
+	 * @return a^b (mod c)
+	 */
+  	public int modPow(long a, long b, int c) {
+  		return modPowCore(a % c, b, c);
+  	}
+
 	/**
 	 * Computes a^b (mod c) for <code>a</code> int, <code>b</code> long, <code>c</code> int. Very fast.
 	 * @param a

src/main/java/de/tilman_neumann/jml/modular/ModularSqrt.java

@@ -191,14 +191,14 @@ private int bruteForce(BigInteger n, int p) {
 	 * Works for any odd p with t^2 == n (mod p) having solution t>0.
 	 * Implementation for arguments having int solutions.
 	 * 
-	 * @param n
+	 * @param n a positive BigInteger having Jacobi(n|p) = 1
 	 * @param power p^exponent
 	 * @param last_power p^(exponent-1)
 	 * @param t solution of t^2 == n (mod p)
 	 * 
 	 * @return sqrt of n (mod p^exponent)
 	 */
-	public int modularSqrtModPower(BigInteger n, int power, int last_power, int t) {
+	public int modularSqrtModPower(BigInteger n, int power, int last_power, long t) {
 		// Barthel's e = (power - 2*last_power + 1)/2
 		int f = (power - (last_power<<1) + 1)>>1;
 		// square root == n (mod p^exponent)

src/main/java/de/tilman_neumann/jml/modular/ModularSqrt31.java

@@ -174,7 +174,7 @@ int case5Mod8(int n, int p) { // not private because used in tests
 	 * @param p
 	 * @return (the smaller) sqrt of n (mod p)
 	 */
-	int bruteForce(int n, int p) { // not private because used in tests
+	private int bruteForce(int n, int p) { // not private because used in tests
 		//boolean foundT = false;
 		int nModP = n%p;
 		int t;
@@ -204,14 +204,14 @@ int bruteForce(int n, int p) { // not private because used in tests
 	 * Works for any odd p with t^2 == n (mod p) having solution t>0.
 	 * Implementation for arguments having int solutions.
 	 * 
-	 * @param n a positive integer having Jacobi(n|p) = 1
+	 * @param n a positive long having Jacobi(n|p) = 1
 	 * @param power p^exponent
 	 * @param last_power p^(exponent-1)
 	 * @param t solution of t^2 == n (mod p)
 	 * 
 	 * @return sqrt of n (mod p^exponent)
 	 */
-	public int modularSqrtModPower(int n, int power, int last_power, int t) {
+	public int modularSqrtModPower(long n, int power, int last_power, long t) {
 		// Barthel's e = (power - 2*last_power + 1)/2
 		int f = (power - (last_power<<1) + 1)>>1;
 		// square root == n (mod p^exponent)