C++ Tutorial/Data Types/Your stack
Содержание
a stack as a class
<source lang="cpp">#include <iostream>
using namespace std;
class Stack {
private:
enum { MAX = 10 };
int st[MAX];
int top;
public:
Stack(){ top = 0; }
void push(int var) { st[++top] = var; }
int pop(){ return st[top--]; }
};
int main(){
Stack s1;
s1.push(11);
s1.push(22);
cout << "1: " << s1.pop() << endl; //22
cout << "2: " << s1.pop() << endl; //11
s1.push(33);
s1.push(44);
s1.push(55);
s1.push(66);
cout << "3: " << s1.pop() << endl; //66
cout << "4: " << s1.pop() << endl; //55
cout << "5: " << s1.pop() << endl; //44
cout << "6: " << s1.pop() << endl; //33
return 0;
}</source>
Declare your own class stack
<source lang="cpp">#include <iostream> using namespace std; const int SIZE=100; class stack {
int stck[SIZE]; int tos;
public:
stack() {
tos=0;
}
void push(int i)
{
if(tos==SIZE) {
cout << "Stack is full.\n";
return;
}
stck[tos] = i;
tos++;
}
int pop()
{
if(tos==0) {
cout << "Stack underflow.\n";
return 0;
}
tos--;
return stck[tos];
}
operator int() {
return tos;
}
}; int main() {
stack stck; int i, j; for(i=0; i<20; i++) stck.push(i); j = stck; // convert to integer cout << j << " items on stack.\n"; cout << SIZE - stck << " spaces open.\n"; return 0;
}</source>
20 items on stack. 80 spaces open.
Generic stack
<source lang="cpp">#include <iostream>
using std::cout; using std::cin; using std::endl; template< class T > class Stack { public:
Stack( int = 10 );
~Stack() { delete [] stackPtr; }
bool push( const T& );
bool pop( T& );
private:
int size;
int top;
T *stackPtr;
bool isEmpty() const { return top == -1; }
bool isFull() const { return top == size - 1; }
}; template< class T > Stack< T >::Stack( int s ) {
size = s > 0 ? s : 10; top = -1; stackPtr = new T[ size ];
} template< class T > bool Stack< T >::push( const T &pushValue ) {
if ( !isFull() ) {
stackPtr[ ++top ] = pushValue;
return true;
}
return false;
} template< class T > bool Stack< T >::pop( T &popValue ) {
if ( !isEmpty() ) {
popValue = stackPtr[ top-- ];
return true;
}
return false;
}
int main() {
Stack< double > doubleStack( 5 );
double f = 1.1;
cout << "Pushing elements onto doubleStack\n";
while ( doubleStack.push( f ) ) {
cout << f << " ";
f += 1.1;
}
cout << f;
while ( doubleStack.pop( f ) )
cout << f << " ";
Stack< int > intStack;
int i = 1;
while ( intStack.push( i ) ) {
cout << i << " ";
++i;
}
cout << i ;
while ( intStack.pop( i ) )
cout << i << " ";
return 0;
}</source>
generic stack implementation
<source lang="cpp">#include <assert.h> typedef void* generic_ptr;
- include <iostream>
using namespace std; class stack { public:
explicit stack(int size = 1000): max_len(size), top(EMPTY) {
s = new generic_ptr[size];
assert(s != 0);
}
~stack() { delete [] s; }
void reset() { top = EMPTY; }
void push(generic_ptr c) { s[++top] = c; }
generic_ptr pop() { return s[top--]; }
generic_ptr top_of() { return s[top]; }
bool empty()const { return top == EMPTY; }
bool full()const { return top == max_len - 1; }
private:
enum { EMPTY = -1};
generic_ptr* s;
int max_len;
int top;
};
char* months[12] = { "january", "february", "march",
"april", "may", "june", "july", "august",
"september", "october", "november", "december"};
int main() {
stack a;
int i;
for (i = 0; i < 12; ++i)
a.push(months[i]);
for (i = 0; i < 12; ++i)
cout << reinterpret_cast<char*>(a.pop()) << endl;
}</source>
Stack implementation with constructor
<source lang="cpp">#include <iostream>
- include <assert.h>
using namespace std; class ch_stack { public:
explicit ch_stack(int size): max_len( size), top(EMPTY)
{ assert(size > 0);s = new char[size]; assert(s != 0);}
ch_stack();
ch_stack(const ch_stack& str);
ch_stack(int size, const char str[]);
~ch_stack() { delete []s; }
void reset() { top = EMPTY; }
void push(char c) { s[++top]= c; }
char pop() { return s[top--]; }
char top_of() const { return s[top]; }
bool empty() const { return (top == EMPTY); }
bool full() const { return (top == max_len - 1); }
private:
enum { EMPTY = -1 };
char* s;
int max_len;
int top;
}; //default constructor for ch_stack ch_stack::ch_stack():max_len(100),top(EMPTY) {
s = new char[100]; assert(s != 0);
} //domain transfer ch_stack::ch_stack(int size, const char str[]):
max_len(size)
{
int i;
assert(size > 0);
s = new char[size];
assert(s != 0);
for (i = 0; i < max_len && str[i] != 0; ++i)
s[i] = str[i];
top = --i;
} //Copy constructor for ch_stack of characters ch_stack::ch_stack(const ch_stack& str):
max_len(str.max_len),top(str.top)
{
s = new char[str.max_len]; assert(s != 0); memcpy(s, str.s, max_len);
} int cnt_char(char c, ch_stack s) {
int count = 0;
while (!s.empty())
count += (c == s.pop());
return count;
} int main() {
ch_stack typea(100);
ch_stack typeb;
ch_stack typec(50, "this is a test");
ch_stack typed(typec);
char reverseline[200];
char a [30] = {"aaaa"};
char b [40] = {"bbbb"};
int i = 0;
cout << cnt_char("a", typec) << endl;
typea.reset();
while (a[i])
if (!typea.full())
typea.push(a[i++]);
i = 0;
while (!typea.empty())
reverseline[i++] = typea.pop();
reverseline[i] = "\0";
cout << reverseline;
i = 0;
while (b[i])
if (!typeb.full())
typeb.push(b[i++]);
i = 0;
while (!typeb.empty())
reverseline[i++] = typeb.pop();
reverseline[i] = "\0";
cout << reverseline;
i = 0;
while (!typec.empty())
reverseline[i++] = typec.pop();
reverseline[i] = "\0";
cout << reverseline;
i = 0;
while (!typed.empty())
reverseline[i++] = typed.pop();
reverseline[i] = "\0";
cout << reverseline;
}</source>
