大整數類（已完善）
阿新 • • 發佈：2019-01-25
this include while maxsize space tor istream lse cstring
在這裏吐槽CSDN,代碼保存在CSDN上面，復制下來變成一堆亂碼，垃圾的要死。以後慢慢轉博客園
偷偷告訴你們，python的的大數可以像c語言的int類型使用，打算學python了
#include<iostream> #include<cstring> #include<iomanip> #include<algorithm> #include<cstdlib> #include<cstdio> using namespace std; #define MAXN 9999 #define MAXSIZE 1000 #defineDLEN 4 class BigNum { private: int a[MAXSIZE]; //可以控制大數的位數 int len; //大數長度 public: BigNum() { len = 1; memset(a, 0, sizeof(a)); } //構造函數 BigNum(const int); //將一個int類型的變量轉化為大數 BigNum(const char*); //將一個字符串類型的變量轉化為大數 BigNum(const BigNum &); //拷貝構造函數 BigNum &operator=(const BigNum &); //重載賦值運算符，大數之間進行賦值運算 friend istream& operator>>(istream&, BigNum&); //重載輸入運算符 friend ostream& operator<<(ostream&, BigNum&); //重載輸出運算符 BigNum operator+(const BigNum &) const; //重載加法運算符，兩個大數之間的相加運算 BigNum operator-(constBigNum &) const; //重載減法運算符，兩個大數之間的相減運算 BigNum operator*(const BigNum &) const; //重載乘法運算符，兩個大數之間的相乘運算 BigNum operator/(const int &) const; //重載除法運算符，大數對一個整數進行相除運算 BigNum operator^(const int &) const; //大數的n次方運算 int operator%(const int &) const; //大數對一個int類型的變量進行取模運算 bool operator>(const BigNum & T)const; //大數和另一個大數的大小比較 bool operator>(const int & t)const; //大數和一個int類型的變量的大小比較 void print(); //輸出大數 }; BigNum::BigNum(const int b) //將一個int類型的變量轉化為大數 { int c, d = b; len = 0; memset(a, 0, sizeof(a)); while (d > MAXN) { c = d - (d / (MAXN + 1)) * (MAXN + 1); d = d / (MAXN + 1); a[len++] = c; } a[len++] = d; } BigNum::BigNum(const char*s) //將一個字符串類型的變量轉化為大數 { int t, k, index, l, i; memset(a, 0, sizeof(a)); l = strlen(s); len = l / DLEN; if (l%DLEN) len++; index = 0; for (i = l - 1; i >= 0; i -= DLEN) { t = 0; k = i - DLEN + 1; if (k < 0) k = 0; for (int j = k; j <= i; j++) t = t * 10 + s[j] - ‘0‘; a[index++] = t; } } BigNum::BigNum(const BigNum & T) : len(T.len) //拷貝構造函數 { int i; memset(a, 0, sizeof(a)); for (i = 0; i < len; i++) a[i] = T.a[i]; } BigNum & BigNum::operator=(const BigNum & n) //重載賦值運算符，大數之間進行賦值運算 { int i; len = n.len; memset(a, 0, sizeof(a)); for (i = 0; i < len; i++) a[i] = n.a[i]; return *this; } istream& operator>>(istream & in, BigNum & b) //重載輸入運算符 { char ch[MAXSIZE * 4]; int i = -1; in >> ch; int l = strlen(ch); int count = 0, sum = 0; for (i = l - 1; i >= 0;) { sum = 0; int t = 1; for (int j = 0; j < 4 && i >= 0; j++, i--, t *= 10) { sum += (ch[i] - ‘0‘)*t; } b.a[count] = sum; count++; } b.len = count++; return in; } /*ostream& operator<<(ostream& out, BigNum& b) //重載輸出運算符 { int i; cout << b.a[b.len - 1]; for(i = b.len - 2 ; i >= 0 ; i--) { cout.width(DLEN); cout.fill(‘0‘); cout << b.a[i]; } return out; }*/ BigNum BigNum::operator+(const BigNum & T) const //兩個大數之間的相加運算 { BigNum t(*this); int i, big; //位數 big = T.len > len ? T.len : len; for (i = 0; i < big; i++) { t.a[i] += T.a[i]; if (t.a[i] > MAXN) { t.a[i + 1]++; t.a[i] -= MAXN + 1; } } if (t.a[big] != 0) t.len = big + 1; else t.len = big; return t; } BigNum BigNum::operator-(const BigNum & T) const //兩個大數之間的相減運算 { int i, j, big; bool flag; BigNum t1, t2; if (*this > T) { t1 = *this; t2 = T; flag = 0; } else { t1 = T; t2 = *this; flag = 1; } big = t1.len; for (i = 0; i < big; i++) { if (t1.a[i] < t2.a[i]) { j = i + 1; while (t1.a[j] == 0) j++; t1.a[j--]--; while (j > i) t1.a[j--] += MAXN; t1.a[i] += MAXN + 1 - t2.a[i]; } else t1.a[i] -= t2.a[i]; } t1.len = big; while (t1.a[len - 1] == 0 && t1.len > 1) { t1.len--; big--; } if (flag) t1.a[big - 1] = 0 - t1.a[big - 1]; return t1; } BigNum BigNum::operator*(const BigNum & T) const //兩個大數之間的相乘運算 { BigNum ret; int i, j, up; int temp, temp1; for (i = 0; i < len; i++) { up = 0; for (j = 0; j < T.len; j++) { temp = a[i] * T.a[j] + ret.a[i + j] + up; if (temp > MAXN) { temp1 = temp - temp / (MAXN + 1) * (MAXN + 1); up = temp / (MAXN + 1); ret.a[i + j] = temp1; } else { up = 0; ret.a[i + j] = temp; } } if (up != 0) ret.a[i + j] = up; } ret.len = i + j; while (ret.a[ret.len - 1] == 0 && ret.len > 1) ret.len--; return ret; } BigNum BigNum::operator/(const int & b) const //大數對一個整數進行相除運算 { BigNum ret; int i, down = 0; for (i = len - 1; i >= 0; i--) { ret.a[i] = (a[i] + down * (MAXN + 1)) / b; down = a[i] + down * (MAXN + 1) - ret.a[i] * b; } ret.len = len; while (ret.a[ret.len - 1] == 0 && ret.len > 1) ret.len--; return ret; } int BigNum::operator %(const int & b) const //大數對一個int類型的變量進行取模運算 { int i, d = 0; for (i = len - 1; i >= 0; i--) { d = ((d * (MAXN + 1)) % b + a[i]) % b; } return d; } BigNum BigNum::operator^(const int & n) const //大數的n次方運算 { BigNum t, ret(1); int i; if (n < 0) exit(-1); if (n == 0) return 1; if (n == 1) return *this; int m = n; while (m > 1) { t = *this; for (i = 1; i << 1 <= m; i <<= 1) { t = t * t; } m -= i; ret = ret * t; if (m == 1) ret = ret * (*this); } return ret; } bool BigNum::operator>(const BigNum & T) const //大數和另一個大數的大小比較 { int ln; if (len > T.len) return true; else if (len == T.len) { ln = len - 1; while (a[ln] == T.a[ln] && ln >= 0) ln--; if (ln >= 0 && a[ln] > T.a[ln]) return true; else return false; } else return false; } bool BigNum::operator >(const int & t) const //大數和一個int類型的變量的大小比較 { BigNum b(t); return *this > b; } void BigNum::print() //輸出大數 { int i; //cout << a[len - 1]; printf("%d", a[len - 1]); for (i = len - 2; i >= 0; i--) { /*cout.width(DLEN); cout.fill(‘0‘); cout << a[i];*/ printf("%04d", a[i]); } //cout << endl; printf("\n"); } int main(void) { char s[10005]; cin >> s; BigNum n = s; n = n * 2; n = n + 1; BigNum t = 3; for (int ans = 0; ans < 100000000; ans++) { if (n > (t^ans)) { continue; } cout << ans << endl; break; } return 0; }
大整數類（已完善）