小编Coo*_*ect的帖子

想象一个实例BigInteger,然后在创建实例后如何初始化它？

例如:

BigInteger t = new BigInteger();

如何投入价值t？

如果无法调用构造函数,那么可以做什么,将值放在对象中？

错误---模数不正

BigInteger正在考虑vaule 0或-ve,但我无法弄清楚在哪里

public int[] conCheck(BigInteger big)
{
    int i=0,mul=1;
    int a[]= new int[10];
    int b[]= new int[10];
    BigInteger rem[]= new BigInteger[11]; 
    BigInteger num[]= new BigInteger[11]; 


    String s="100000000";//,g="9";
    //for(i=0;i<5;i++)
    //s=s.concat(g);

    BigInteger divi[]= new BigInteger[11]; 
    divi[0]=new BigInteger(s);
    num[0]=big; 
    for(i=0;i<10;i++)  
    {    
        int z = (int)Math.pow((double)10,(double)(i+1));
        BigInteger zz = new BigInteger(String.valueOf(z));
        divi[i+1]=divi[i].divide(zz);
        num[i+1]=num[i].divide(zz);
    }

{   for(i=0;i<10;i++) 

    {
        rem[i] = num[i].mod(divi[i]);       
        b[i]=rem[i].intValue();
        if(i>=4)
        {
            mul= b[i]*b[i-1]*b[i-2]*b[i-3]*b[i-4]; 
        }

        a[i]=mul;
    }
    }


    return a;


}

在控制台上出错

C:\jdk1.6.0_07\bin>java euler/BigConCheck1
Exception in thread "main" java.lang.ArithmeticException: BigInteger: modulus no …

获得以下运行时错误

C:\jdk1.6.0_07\bin>java euler/BigConCheck
Exception in thread "main" java.lang.NumberFormatException: For input string: "z
"
        at java.lang.NumberFormatException.forInputString(NumberFormatException.
java:48)
        at java.lang.Integer.parseInt(Integer.java:447)
        at java.math.BigInteger.<init>(BigInteger.java:314)
        at java.math.BigInteger.<init>(BigInteger.java:447)
        at euler.BigConCheck.conCheck(BigConCheck.java:25)
        at euler.BigConCheck.main(BigConCheck.java:71)

我的守则

package euler;
import java.math.BigInteger;
class BigConCheck
{

public int[] conCheck(BigInteger big)
{
    int i=0,q=0,w=0,e=0,r=0,t=0,mul=1;
    int a[]= new int[1000];
    int b[]= new int[7];
    BigInteger rem[]= new BigInteger[4]; 
    BigInteger num[]= new BigInteger[4]; 
    for(i=0;i<4;i++)  
    num[i]=big;   // intialised num[1 to 4][0] with big
    String s="1",g="0";
    for(i=0;i<999;i++)
    s = s.concat(g);
    BigInteger divi[]= new BigInteger[4]; 

    for(i=0;i<5;i++)  
    {
        divi[i]=new BigInteger(s); …

运行时异常 - java.lang.ClassCastingException......

Integer intArr[] = new Integer[arrList.size()];
ArrayList <Integer> arrList =new ArrayList();
intArr=(Integer[])arrList.toArray(); // returns Object class which is downcaste to Integer;

我知道降级不安全,但为什么会这样呢？我也试图转换ArrayList到String以Integer对int,但我得到了同样的错误.

为什么这会让人高兴呢

double zero = 0.0;    
double a[] = { 0,0,0,0,0, zero/zero}; // NaN
cout << (a[5] == 5[a] ? "true" : "false") << endl;

版画

false