C++大数运算

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转载最新推荐文章于 2026-07-27 07:31:47 发布 729 阅读 AI 写同款· GEO 优化 ›

c++语言大数与大数的运算,N！ 1.大数加大数之模拟手工算法：（注：这里的代码不是很完善、简洁和公整，请见谅）这里介绍的这种方法是大数加大数就是利用两个字符窜，从后一直往前加。这里只考虑了str1字符串比str2字符串长， #include #include using namespace std; int main() { string str1, str2; while (cin >> str1 >> st 阅读详情

    #include<cstdio>  
    #include<iostream>  
    using namespace std;  

    const int maxn = 200;  
    struct bign{  
      int len, s[maxn];  

      bign() {  
        memset(s, 0, sizeof(s));  
        len = 1;  
      }  

      bign(int num) {  
        *this = num;  
      }  

      bign(const char* num) {  
        *this = num;  
      }  

      bign operator = (int num) {  
        char s[maxn];  
        sprintf(s, "%d", num);  
        *this = s;  
        return *this;  
      }  

      bign operator = (const char* num) {  
        len = strlen(num);  
        for(int i = 0; i < len; i++) s[i] = num[len-i-1] - '0';  
        return *this;  
      }  

      string str() const {  
        string res = "";  
        for(int i = 0; i < len; i++) res = (char)(s[i] + '0') + res;  
        if(res == "") res = "0";  
        return res;  
      }  

      bign operator + (const bign& b) const{  
        bign c;  
        c.len = 0;  
        for(int i = 0, g = 0; g || i < max(len, b.len); i++) {  
          int x = g;  
          if(i < len) x += s[i];  
          if(i < b.len) x += b.s[i];  
          c.s[c.len++] = x % 10;  
          g = x / 10;  
        }  
        return c;  
      }  

      void clean() {  
        while(len > 1 && !s[len-1]) len--;  
      }  

      bign operator * (const bign& b) {  
        bign c; c.len = len + b.len;  
        for(int i = 0; i < len; i++)  
          for(int j = 0; j < b.len; j++)  
            c.s[i+j] += s[i] * b.s[j];  
        for(int i = 0; i < c.len-1; i++){  
          c.s[i+1] += c.s[i] / 10;  
          c.s[i] %= 10;  
        }  
        c.clean();  
        return c;  
      }  

      bign operator - (const bign& b) {  
        bign c; c.len = 0;  
        for(int i = 0, g = 0; i < len; i++) {  
          int x = s[i] - g;  
          if(i < b.len) x -= b.s[i];  
          if(x >= 0) g = 0;  
          else {  
            g = 1;  
            x += 10;  
          }  
          c.s[c.len++] = x;  
        }  
        c.clean();  
        return c;  
      }  

      bool operator < (const bign& b) const{  
        if(len != b.len) return len < b.len;  
        for(int i = len-1; i >= 0; i--)  
          if(s[i] != b.s[i]) return s[i] < b.s[i];  
        return false;  
      }  

      bool operator > (const bign& b) const{  
        return b < *this;  
      }  

      bool operator <= (const bign& b) {  
        return !(b > *this);  
      }  

      bool operator == (const bign& b) {  
        return !(b < *this) && !(*this < b);  
      }  

      bign operator += (const bign& b) {  
        *this = *this + b;  
        return *this;  
      }  
    };  

    istream& operator >> (istream &in, bign& x) {  
      string s;  
      in >> s;  
      x = s.c_str();  
      return in;  
    }  

    ostream& operator << (ostream &out, const bign& x) {  
      out << x.str();  
      return out;  
    }  

    int main() {  
      bign a, b;  
      cin >> a >> b;  
      a += b;  
      cout << a << endl;  
      return 0;  
    }