Huge Integer

#include <iostream> #include <string> using namespace std; class HugeInteger { public: HugeInteger(); HugeInteger(char*); void input(); void print(); bool isZero() const; bool isEqualTo(const HugeInteger&); bool isGreaterThan(const HugeInteger&); bool isLessThan(const HugeInteger&); HugeInteger Add(const HugeInteger&); HugeInteger Sub(const HugeInteger&); HugeInteger Multiply(const HugeInteger& b); HugeInteger Divide(const HugeInteger& b); private: int intArray[40]; int size; void setZero(); }; void HugeInteger::setZero() { for (int i = 0; i<40; i++) intArray[i] = 0; size=1; } bool HugeInteger::isZero() const { for (int i = 0; i<40; i++) if (intArray[i] != 0) return false; return true; } HugeInteger::HugeInteger() { setZero(); } HugeInteger::HugeInteger(char *p) { setZero(); size = strlen(p); for (int i=0; i<size; i++) intArray[i]=p[size-1-i]-'0'; } void HugeInteger::input() { char p[40]; setZero(); cin >> p; size = strlen(p); for (int i=0; i<size; i++) intArray[i]=p[size-1-i]-'0'; } void HugeInteger::print() { for (int i =size-1; i>=0; i--) cout<< intArray[i]; cout<<endl; } bool HugeInteger::isEqualTo(const HugeInteger& b) { if (size!=b.size) return false; for(int i=0; i<size; i++) { if(intArray[i]!= b.intArray[i]) return false; } return true; } bool HugeInteger::isGreaterThan(const HugeInteger& b) { if (size<b.size) return false; if (size>b.size) return true; for(int i=size-1; i>=0; i--) { if(intArray[i]< b.intArray[i]) return false; if(intArray[i]>b.intArray[i]) return true; } return false; } bool HugeInteger::isLessThan(const HugeInteger& b) { if (size>b.size) return false; if (size<b.size) return true; for(int i=size-1; i>0; i--) { if(intArray[i]> b.intArray[i]) return false; if(intArray[i]<b.intArray[i]) return true; } return false; } HugeInteger HugeInteger::Add(const HugeInteger& b) { int c=0; HugeInteger temp; if (b.isZero()) return *this; if (this->isZero()) return b; int max = size>b.size? size: b.size; for (int i = 0; i<max; i++) { temp.intArray[i] = intArray[i]+b.intArray[i]+c; if (temp.intArray[i]>9){ c = 1; temp.intArray[i]-=10; } else c=0; } if (c==1){ if (max==40) { cout<< "overflow!"; temp.setZero(); return *this; } temp.size = max+1; temp.intArray[max]=1; } else temp.size = max; return temp; } HugeInteger HugeInteger::Sub(const HugeInteger& b) { int c=0; HugeInteger temp; if (this->isLessThan(b)) { cout<<"Nagtive number is not supported"; return temp; } for (int i = 0; i<size; i++) { temp.intArray[i] = intArray[i]-b.intArray[i]-c; if (temp.intArray[i]<0){ c = 1; temp.intArray[i]+=10; } else c=0; } return temp; } HugeInteger HugeInteger::Multiply(const HugeInteger& b) { int c=0; HugeInteger temp,result; if (b.isZero()||this->isZero()) return temp; for (int i = 0; i<b.size; i++) { c=0; temp.setZero(); for(int j=0; j<size; j++) { temp.intArray[i+j] = intArray[j]*b.intArray[i]+c; c=temp.intArray[i+j]/10; temp.intArray[i+j]%=10; } temp.size = size+i; if (c>0) { temp.size++; if (temp.size ==40) { cout<<"overflow"; temp.setZero(); return temp; } temp.intArray[temp.size-1]=c; } result = result.Add(temp); } return result; } HugeInteger HugeInteger::Divide(const HugeInteger &b) { int c=0; int i,j; HugeInteger temp, tempa,tempb,result; if (b.isZero()) { cout<<"mistake! divisor cannot be zero"; return result; } if (this->isLessThan(b)) return result; c= size-b.size; tempa = *this; tempb.size = tempa.size; for ( j=b.size-1; j>=0; j--) tempb.intArray[j+c]= b.intArray[j]; for (i=c; i>=0; i--) { while(!tempa.isLessThan(tempb)) { tempa = tempa.Sub(tempb); result.intArray[i]++; } tempb.size--; for( j=0; j<tempb.size; j++) tempb.intArray[j]=tempb.intArray[j+1]; tempb.intArray[tempb.size]=0; } if(result.intArray[c]==0) result.size = c; else result.size = c+1; return result; } int main() { HugeInteger a("123456"),b,c; cout<<"a="; a.print(); cout<<"b="; b.input(); if (b.isGreaterThan(a)) cout<< "b is greater than a"<<endl; if (a.isLessThan(b)) cout<<"a is Less than b"<<endl; cout<<"a+b="; c=b.Add(a); c.print(); cout<<"a-b="; c=a.Sub(b); c.print(); cout<<"a*b="; c=a.Multiply(b); c.print(); return 0; }