java - 执行大整数 Java 程序时出现错误

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我编写了一个用于操作最多 40 位整数的 java 程序，但在编译时出现一些错误，我不知道为什么。你能帮我吗？下面我放了我的代码。包括两个类:

public class HugeInteger {

private int[] array = new int[40];

public HugeInteger() {
    for (int i = 0; i <= 40; i++) {
        array[i] = 0;
    }

}

/**
 *
 * @param str
 */
public HugeInteger(String str) {

    if (str.length() > 41) {
        System.out.printf("More than 40 digits");
    }

    int i;
    if (str.charAt(0) == '-') {
        array[0] = -1;
    } else if (str.charAt(0) != '0') {
        array[0] = 1;
    }
    for (i = 0; i < 40; i++) {
        if ((str.charAt(i) != '1') || (str.charAt(i) != '2') || (str.charAt(i) != '3') || (str.charAt(i) != '4') || (str.charAt(i) != '5') || (str.charAt(i) != '6') || (str.charAt(i) != '7') || (str.charAt(i) != '8') || (str.charAt(i) != '9') || (str.charAt(i) != '0')) {
            System.out.printf("Not number");
            break;
        }

        char chr = str.charAt(i);
        Integer dig = Integer.parseInt(String.valueOf(chr));
        array[i + 1] = dig;

    }
}

/**
 * This method overrides the toString and it is used for printing the
 * object.
 *
 * @return string
 */
@Override
public String toString() {
    String str = "";
    for (int i = 0; i < 40; i++) {
        str = str.concat(String.valueOf(array[i]));
    }
    return str;
}

/**
 * This method adds two number together and returns their result.
 *
 * @param hg It's the second number to be added
 * @return result After adding two number result will be saved in result.
 *
 */
public HugeInteger Sum(HugeInteger hg) {
    HugeInteger result = new HugeInteger();
    int c = 0;
    if (array[0] == 1 && hg.array[0] == 1) {
        for (int i = 40; i >= 1; i--) {
            result.array[i] = array[i] + hg.array[i] + c;
            if (result.array[i] > 9) {
                c = 1;
                result.array[i] = result.array[i] % 10;
            } else {
                c = 0;
            }

        }
        result.array[0] = 1;
    } else if (array[0] == 1 && hg.array[0] == -1) {
        hg.array[0] = 1;
        result = Subtract(hg);
    } else if (array[0] == -1 && hg.array[0] == 1) {
        array[0] = 1;
        result = Subtract(hg);
        result.array[0] = (-1) * result.array[0];

    } else if (array[0] == -1 && hg.array[0] == -1) {
        for (int i = 40; i >= 1; i--) {
            result.array[i] = array[i] + hg.array[i] + c;
            if (result.array[i] > 9) {
                c = 1;
                result.array[i] = result.array[i] % 10;
            } else {
                c = 0;
            }

        }
        result.array[0] = -1;

    }

    return result;
}

/**
 * This method subtracts two number together and returns their result.
 *
 * @param hg It's the second number to be subtracted
 * @return result After subtracting two number result will be saved in
 * result.
 */
public HugeInteger Subtract(HugeInteger hg) {
    HugeInteger result = new HugeInteger();
    int c = 0;
    if (array[0] == 1 && hg.array[0] == 1) {
        if (array[1] > hg.array[1]) {
            for (int i = 40; i >= 1; i--) {
                if ((array[i] - c) < hg.array[i]) {
                    result.array[i] = (10 + array[i] - c) - hg.array[i];
                    c = 1;
                } else {
                    result.array[i] = (array[i] - c) - hg.array[i];
                    c = 0;
                }
            }
            for (int i = 0; i <= 40; i++) {
                if (array[i] != 0) {
                    array[0] = 1;
                    break;
                }

            }

        } else {
            for (int i = 40; i >= 1; i--) {
                if ((array[i] - c) < hg.array[i]) {
                    result.array[i] = (10 + hg.array[i] - c) - array[i];
                    c = 1;
                } else {
                    result.array[i] = (hg.array[i] - c) - array[i];
                    c = 0;
                }
            }
            result.array[0] = -1;
        }
    }

    if (array[0] == 1 && hg.array[0] == -1) {
        hg.array[0] = 1;
        result = Sum(hg);
    }

    if (array[0] == -1 && hg.array[0] == 1) {
        array[0] = 1;
        result = Sum(hg);
        result.array[0] = (-1) * result.array[0];
    }

    if (array[0] == -1 && hg.array[0] == -1) {
        if (array[1] > hg.array[1]) {
            for (int i = 40; i >= 1; i--) {
                if ((array[i] - c) < hg.array[i]) {
                    result.array[i] = (10 + array[i] - c) - hg.array[i];
                    c = 1;
                } else {
                    result.array[i] = (array[i] - c) - hg.array[i];
                    c = 0;
                }
            }
            for (int i = 0; i <= 40; i++) {
                if (array[i] != 0) {
                    array[0] = 1;
                    break;
                }

            }

        } else {
            for (int i = 40; i >= 1; i--) {
                if ((array[i] - c) < hg.array[i]) {
                    result.array[i] = (10 + hg.array[i] - c) - array[i];
                    c = 1;
                } else {
                    result.array[i] = (hg.array[i] - c) - array[i];
                    c = 0;
                }
            }
            result.array[0] = -1;
        }
        result.array[0] = (-1) * result.array[0];
    }
    return result;
}

public int Sign(HugeInteger hg) {
    return (hg.array[0]);
}

/**
 * This method checks whether the first number is equal to the second one or
 * not.
 *
 * @param hg It's the second number.
 * @return a boolean that reveals that this condition is true or false.
 */
public boolean Equals(HugeInteger hg) {
    boolean res = true;
    for (int i = 0; i <= 40; i++) {
        if (array[i] != hg.array[i]) {
            res = false;
            break;
        }
    }
    return res;
}

/**
 * This method checks whether the first number is greater than the second
 * one or not.
 *
 * @param hg It's the second number.
 * @return a boolean that reveals that this condition is true or false.
 */
public boolean isGreaterThan(HugeInteger hg) {

    for (int i = 0; i <= 40; i++) {
        if (array[i] > hg.array[i]) {
            return true;
        } else if (array[i] < hg.array[i]) {
            return false;
        } else {
            i = i + 1;
        }
    }
    return false;
}

/**
 * This method checks whether the first number is less than the second one
 * or not.
 *
 * @param hg It's the second number.
 * @return a boolean that reveals that this condition is true or false.
 */
public boolean isLessThan(HugeInteger hg) {
    for (int i = 0; i <= 40; i++) {
        if (array[i] < hg.array[i]) {
            return true;
        } else if (array[i] > hg.array[i]) {
            return false;
        } else {
            i = i + 1;
        }
    }
    return false;
}

/**
 * This method checks whether the number is zero or not.
 *
 * @param hg It's the number.
 * @return a boolean that reveals that this condition is true or false.
 */
public boolean isZero(HugeInteger hg) {
    if (array[0] == 0) {
        return true;
    }
    return false;
}

}

主类:

public class Main {

private static ArrayList<String> String;

public static void main(String[] args) {

    ArrayList<HugeInteger> num1 = new ArrayList<>();
    ArrayList<HugeInteger> num2 = new ArrayList<>();
    String line1, line2;
    Scanner stdin = new Scanner(System.in);
    line1 = stdin.nextLine();
    line2 = stdin.nextLine();
    System.out.printf("\n");
    System.out.printf("\n");
    HugeInteger a, b;
    a = new HugeInteger(line1);
    b = new HugeInteger(line2);
    num1.add(a);
    num2.add(b);
    while (true) {
        line1 = stdin.nextLine();
        if (line1.equals("exit")) {
            break;

        }
        line2 = stdin.nextLine();
        System.out.printf("\n");
        a = new HugeInteger(line1);
        b = new HugeInteger(line2);
        num1.add(a);
        num2.add(b);

    }
    int index = 0;
    HugeInteger c, d;

    while (index < num1.size()) {
        c = num1.get(index);
        d = num2.get(index);
        System.out.printf("Sum: ", c.Sum(d));
        System.out.printf("Sub: ", c.Subtract(d));
        System.out.printf("Equals : ", c.Equals(d));
        System.out.printf("isGreaterThan: ", c.isGreaterThan(d));
        System.out.printf("isLessThan: ", c.isLessThan(d));
        index = index + 1;
    }

}

}

Answer 1

只要看看你的问题，你就会在 HugeInteger 类中获取一个最多 40 位数字的字符串。我可以看到您正在尝试创建一个可以处理这么大的数字的新类，但是您的 HugeInteger 类仍然依赖于 Integer 因为您使用

Integer dig = Integer.parseInt(String.valueOf(chr));

Java 中的 Integer 类的最大值为 2147483647 和 -2147483647，因此使用 Integer 类解析 40 位字符串将完全失败。

您发布了很多代码，但本质上您尝试做的事情不会因为我刚才提到的原因而起作用，这将导致依赖于 HugeInteger 的所有其他类和方法无法提供正确或有效的答案。您需要重新考虑您的方法