java.math.BigInteger.isProbablePrime(int certainty) 如果此BigInteger可能是素數,如果其絕對複合返回false。如果確定是≤0,則返回true。
以下是java.math.BigInteger.isProbablePrime()方法的宣告
public boolean isProbablePrime(int certainty)
certainty - 這一措施的呼叫者能容忍的不確定性:如果呼叫返回true,則此BigInteger是素數超過概率(1 - 1/2確定性)。此方法的執行時間正比於該引數的值。
如果此BigInteger可能是素數,如果其絕對複合此方法則返回true。
NA
下面的例子顯示math.BigInteger.isProbablePrime()方法的用法
package com.yiibai; import java.math.*; public class BigIntegerDemo { public static void main(String[] args) { // create 3 BigInteger objects BigInteger bi1, bi2, bi3; // create 3 Boolean objects Boolean b1, b2, b3; // assign values to bi1, bi2 bi1 = new BigInteger("7"); bi2 = new BigInteger("9"); // perform isProbablePrime on bi1, bi2 b1 = bi1.isProbablePrime(1); b2 = bi2.isProbablePrime(1); b3 = bi2.isProbablePrime(-1); String str1 = bi1+ " is prime with certainity 1 is " +b1; String str2 = bi2+ " is prime with certainity 1 is " +b2; String str3 = bi2+ " is prime with certainity -1 is " +b3; // print b1, b2, b3 values System.out.println( str1 ); System.out.println( str2 ); System.out.println( str3 ); } }
讓我們編譯和執行上面的程式,這將產生以下結果:
7 is prime with certainity 1 is true 9 is prime with certainity 1 is false 9 is prime with certainity -1 is true