CArray 2&CHugeInt

好久没来博客了，我决定把这里改造成一个程序媛的博客

HOMEWORK_03_03

<1>二维指针是什么鬼 int** ptr;

HOMEWORK_03_04

<1>静态数组是否需要重载operator= & copy constructor？——NO

the memory space is constructed  separately

<2>when the & is needed?——when you wanted the variable you call to change.

/*Write a class of 2D array

Array2,

And the output of the following code should be :

0, 1, 2, 3,

4, 5, 6, 7,

8, 9, 10, 11,

next

0, 1, 2, 3,

4, 5, 6, 7,

8, 9, 10, 11,*/

#include <iostream> 

using namespace std;

const int MAX = 20;

class Array2{

int row;

int col;

int ** ptr;//二维指针

public:

Array2(int r_ = 0, int c_ = 0,int ** ptr_=NULL) :row(r_), col(c_){

ptr = new int *[r_];

for (int i = 0; i < r_; i++)

ptr[i] = new int[c_];

}

Array2(Array2 &a){

if (a.ptr){

ptr = new int* [a.col];

row = a.row;

col = a.col;

for (int i = 0; i < a.row; i++){

ptr[i] = new int[a.col];

memcpy(ptr[i], a.ptr[i], sizeof(int)*a.col);

}

}

else{

ptr = NULL;

row = 0;

col = 0;

}

}

~Array2(){

row=col=0;

delete[] ptr;

}

Array2& operator =(const Array2& a){

row = a.row;

col = a.col;

if (ptr == a.ptr){

for (int i = 0; i < a.row*a.col; i++)

ptr[i] = a.ptr[i];

return *this;

}

if (ptr)

delete[] ptr;

if (a.ptr){

ptr = new int*[a.col];

for (int i = 0; i < a.row; i++){

ptr[i] = new int[a.col];

memcpy(ptr[i], a.ptr[i], sizeof(int)*a.col);

}

}

else

ptr = NULL;

}

int & operator ()(int subscript_i_, int subscript_j_){

return this->operator[](subscript_i_)[subscript_j_];

}

int *operator [](int subscript){

return ptr[subscript];

}

};

int main()

{

Array2 a(3, 4);

int i, j;

for (i = 0; i < 3; i++)

for (j = 0; j < 4; j++)

a[i][j] = i * 4 + j;

for (i = 0; i < 3; i++) {

for (j = 0; j < 4; j++) {

cout << a(i, j) << ",";

}

cout << endl;

}

cout << "next" << endl;

Array2 b;

b = a;

for (i = 0; i < 3; i++) {

for (j = 0; j < 4; j++) {

cout << b[i][j] << ",";

}

cout << endl;

}

return 0;

}

/*Write a class HugeInt, the output should be :

1)100000089000000 

2)100000089000000

3)10000

4)10000

5)10001

6)10006

7)100000089010006*/

#include <iostream>

#include <cstring> 

#include <cstdlib> 

#include <cstdio> 

const int MAX = 110;

using namespace std;

class CHugeInt{

int length;

int num[MAX];

public:

CHugeInt(char *string);

CHugeInt(int n_);

friend CHugeInt & operator +(CHugeInt & Cn1_,CHugeInt & Cn2_);

friend CHugeInt & operator +(CHugeInt & Cnum_,int num_);

friend CHugeInt & operator +(int num_, CHugeInt & Cnum_);

friend ostream & operator<<(ostream & o, const CHugeInt & Cnum_);

CHugeInt & operator ++(){

*this = *this + 1;

return *this;

}

CHugeInt  operator ++(int){

CHugeInt tmp(*this);

*this = *this + 1;

return tmp;

}

CHugeInt & operator +=(const int num_){

return *this + num_;

}

};

CHugeInt::CHugeInt(char *string){

memset(num, 0, sizeof(int)*MAX);

length = strlen(string);

for (int i = 0; i < length; i++){

char cTmp = string[length - 1 - i];

num[i] = atoi(&cTmp);

}

}

CHugeInt::CHugeInt(int n_){

memset(num, 0, sizeof(int)*MAX);

int i = 0;

for (i = 0; n_; i++){

num[i] = n_ % 10;

n_ = n_ / 10;

}

length = i;

}

CHugeInt & operator +(CHugeInt & Cn1_, CHugeInt & Cn2_){

int LengthMax = 0;

if (Cn1_.length < Cn2_.length)

LengthMax = Cn2_.length;

else

LengthMax = Cn1_.length;

for (int i = 0; i < LengthMax; i++){

int nTmp = Cn1_.num[i] + Cn2_.num[i];

Cn1_.num[i] = nTmp% 10;

Cn1_.num[i + 1] += (nTmp / 10);

}

if (Cn1_.num[LengthMax])

LengthMax++;

Cn1_.length = LengthMax;

return Cn1_;

}

CHugeInt & operator +(CHugeInt & Cnum_,int num_){

CHugeInt tmp = num_;

return Cnum_ + tmp;

}

CHugeInt & operator +(int num_, CHugeInt & Cnum_){

CHugeInt tmp = num_;

return Cnum_ + tmp;

}

ostream & operator<<(ostream & o, const CHugeInt & Cnum_){

for (int i = Cnum_.length - 1; i >= 0; i--)

o << Cnum_.num[i];

return o;

}

int  main()

{

CHugeInt a("1234545436342424354354365289899834234235");

CHugeInt d(9999);

CHugeInt temp = CHugeInt("100000088888888") + 111112;

CHugeInt temp2 = 111112 + CHugeInt("100000088888888");

cout << "1)" << temp << endl;

cout << "2)" << temp2 << endl;

cout << "3)" << ++d << endl;

cout << "4)" << d++ << endl;

cout << "5)" << d << endl;

d += 5;

cout << "6)" << d << endl;

cout << "7)" << d + temp;

return 0;

}