Java 中意外的负数

    import java.util.*;
    public class Prac9FibonacciNumbers {

public static void main(String[] args) {

    int[] x = new int[100];
    x[0] = 1;
    x[1] = 1;

    for (int a = 2; a < 100; a++) {

        x[a] = x[a - 1] + x[a - 2];

    }

    for (int a = 0; a < 100; a++) {

        if(a < 99){

            System.out.print(x[a] + ",");

        }
                else{

                System.out.print(x[a]);

                }

            }

        }

    }

该程序旨在创建斐波那契数列。然而，由于某种原因，它在我的输出中间给了我负数。

我可以用

    Math.abs()

但我想知道为什么它给我负数。输出如下。请帮助我理解这个问题。

1,1,2,3,5,8,13,21,34,55,89,144,233,377,610,987,1597,2584,4181,6765,10946,17711,28657,46368,75025,121393,196418,317811,514 229,832040, 1346269,2178309,3524578,5702887,9227465,14930352,24157817,39088169,63245986,102334155,165580141,267914296,433494437,70140 8733,1134903170,1836311903,-1323752223,512559680,-811192543,-298632863,-1109825406,-1408458269,1776683621 ,368225352,2144908973,-1781832971,363076002,-1418756969,-1055680967,1820529360,764848393,-1709589543,-944741150,164063660 3,695895453,-195​​8435240,-1262539787,1073992269,-188547518,885444751,696897233,1582341984,-2015728079, -433386095,1845853122,1412467027,-103664714​​7,375819880,-660827267,-285007387,-945834654,-1230842041,2118290601,887448560,- 1289228135,-401779575,-1691007710,-2​​092787285,511172301,-1581614984,-1070442683,1642909629, 572466946,-2079590721,-1507123775,708252800,-798870975,-90618175,-889489150,-980107325

斐波那契数列将会快速增长。在第 46 个数字处，您开始得到负数，例如-1323752223。这是因为数字已经变得如此之大以至于溢出了int数据类型。

您可以使用long[]数组，但这只会推迟问题的发生。您将在第 92 个数字处开始得到负数，例如-6246583658587674878，因为它会溢出long数据类型。

Using double不会达到这种量级所需的精度。您可以使用BigIntegers，具有任意精度和大小。

BigInteger[] x = new BigInteger[100];
x[0] = BigInteger.ONE;
x[1] = BigInteger.ONE;

你需要使用add method.

x[a] = x[a - 1].add(x[a - 2]);