本文共 3427 字，大约阅读时间需要 11 分钟。

CHugeInt 类实现大整数运算

代码结构说明

#include 
   
    
#include 
    
     
#include 
     
      
#include 
      
       
using namespace std;
const int MAX = 110;
class CHugeInt {
private:
    char c[200];
    
public:
    // 将字符串反转
    void reverse(char *a) {
        int i = 0, j = strlen(a) - 1;
        while (i < j) {
            swap(a[i], a[j]);
            i++;
            j--;
        }
    }
    CHugeInt(const char* a) {
        int len;
        memset(c, 0, 200);
        strcpy(c, a);
        len = strlen(c);
        reverse(c);
    }
    CHugeInt(int n) {
        int len;
        memset(c, 0, 200);
        sprintf(c, "%d", n);
        len = strlen(c);
        reverse(c);
    }
    CHugeInt operator +(const CHugeInt &b) const {
        CHugeInt a(0);
        int lenb = strlen(b.c);
        int len = strlen(c);
        int lena;
        if (b.c[0] == '0' && lenb == 1) {
            return *this;
        }
        if (c[0] == '0' && len == 1) {
            strcpy(a.c, b.c);
            return a;
        }
        int j = 0;
        for (int i = 0; i < len || i < lenb; i++) {
            int x = 0;
            char c1 = c[i], c2 = b.c[i];
            if (c[i] == 0)
                c1 = '0';
            if (b.c[i] == 0)
                c2 = '0';
            x = c1 - '0' + c2 - '0' + j;
            a.c[i] = (x % 10) + '0';
            j = x / 10;
        }
        lena = len > lenb ? len : lenb;
        if (j != 0) {
            int a0 = len > lenb ? len : lenb;
            a.c[a0] = j + '0';
            lena = a0 + 1;
        }
        return a;
    }
    CHugeInt operator +(int n) {
        return *this + CHugeInt(n);
    }
    friend CHugeInt operator +(int n, const CHugeInt &h) {
        return h + n;
    }
    CHugeInt& operator +=(int n) {
        *this = *this + CHugeInt(n);
        return *this;
    }
    friend CHugeInt& operator ++(CHugeInt &a) {
        a = a + 1;
        return a;
    }
    friend ostream& operator<<(ostream& o, const CHugeInt &a) {
        int len = strlen(a.c);
        for (int i = len - 1; i >= 0; --i) {
            o << a.c[i];
        }
        return o;
    }
    friend CHugeInt operator ++(CHugeInt &a, int) {
        CHugeInt b = a;
        a = (b + 1);
        return b;
    }
};
int main() {
    char s[210];
    int n;
    while (cin >> s >> n) {
        CHugeInt a(s);
        CHugeInt b(n);
        cout << a + b << endl;
        cout << n + a << endl;
        cout << a + n << endl;
        b += n;
        cout << ++b << endl;
        cout << b++ << endl;
        cout << b << endl;
    }
    return 0;
}
      
     
    
   

功能说明

使用示例

程序通过 cin 读取输入的两个非负整数 s 和 n，其中 s 最多可以有 200 位，n 则可以用 int 型表示。对于每组输入，程序输出六行结果，分别是：

样例输入

99999999999999999999999999888888888888888812345678901234567789 126 6

样例输出

999999999999999999999999998888888888888888123456789012345678019999999999999999999999999988888888888888881234567890123456780199999999999999999999999999888888888888888812345678901234567801252526121212131314

程序能够正确处理大整数的加法运算和自增操作，并输出预期结果。

转载地址：http://lvhv.baihongyu.com/