intstack.cpp

来自「Thinking in C 电子书的源代码」· C++ 代码 · 共 44 行

#include "intstack.h"

StackOfInt::StackOfInt(int stk_size)
{
    data = new int[length = stk_size];
    ptr = 0;
};

void StackOfInt::push(int x)
{
    if (ptr < length)
        data[ptr++] = x;
    else
        throw "overflow";
}

int StackOfInt::pop()
{
    if (ptr > 0)
        return data[--ptr];
    else
        throw "underflow";
}

int StackOfInt::top() const
{
    if (ptr > 0)
        return data[ptr-1];
    else
        throw "underflow";
}

int StackOfInt::size() const
{
    return ptr;
}

StackOfInt::~StackOfInt()
{
    delete [] data;
}