栈与队列相关

栈的基础操作：

#include <iostream>
#include <algorithm>
#include <string>
#include <stack>
#include <cstring>
using namespace std;

const int maxnsize=100;

typedef struct Stack
{
    int* data;
    int top;
    int maxnsize;
}SqStack;

void InitStack(SqStack &s, int n)
{
    s.data = new int [n];
    s.top = -1;
    s.maxnsize = n;
}

bool StackEmpty(SqStack &s)
{
    if(s.top == -1)
        return true;
    return false;
}

bool Push(SqStack &s, int x)
{
    if(s.top == s.maxnsize-1)
        return false;
    s.data[++s.top] = x;
    return true;
}

bool Pop(SqStack &s, int &x)
{
    if(s.top == -1)
        return false;
    x = s.data[s.top--];
    return true;
}

bool GetTop(SqStack &s, int &x)
{
    if(s.top == -1)
        return false;
    x = s.data[s.top];
    return true;
}

///3.2)编写算法，判定所给的操作序列是否合法，合法返回true
int The_three_problem(char c[])
{
    ///两个点，出栈操作是否合法。终态是否为空.
    int i=0;
    int p=0, q=0;
    while(c[i] != '\0')
    {
        if(c[i] == 'I')
        {
            p++;
        }
        else if(c[i] == 'O')
        {
            q++;
        }
        if(q>p)
            return 0;
        i++;
    }
    cout<<p<<" "<<q<<endl;
    if(p != q)
        return -1;
    return 1;
}

int main()
{
    ios::sync_with_stdio(false);
    //char a[] = {'I', 'O', 'I', 'I', 'O', 'I', 'O', 'O'};
    //char b[] = {'I', 'O', 'O', 'I', 'O', 'I', 'I', 'O'};
    //char c[] = {'I', 'I', 'I', 'O', 'I', 'O', 'I', 'O'};
    char d[] = {'I', 'I', 'I', 'O', 'O', 'I', 'O', 'O'};
   // cout<<The_three_problem(a)<<endl;
    //cout<<The_three_problem(b)<<endl;
   // cout<<The_three_problem(c)<<endl;
    cout<<The_three_problem(d)<<endl;
    return 0;
}

两个栈共享存储空间，进栈出栈代码如下（王道第五题）：

#include <iostream>
#include <algorithm>
#include <string>
#include <stack>
#include <cstring>
using namespace std;

const int maxnsize=100;

typedef struct Stack
{
    int data[maxnsize];
    int top[2];
}Stk;

void InitStack(Stk &s)
{
    s.top[0] = -1;
    s.top[1] = maxnsize;
}

int push(Stk &s, int i, int x)
{
    if(i<0 || i>1)
        return 0;
    if(s.top[1] - s.top[0] == 1)
        return 0;
    switch(i){
        case 0:s.data[++s.top[0]] = x;break;
        case 1:s.data[--s.top[1]] = x;break;
    }
    return 1;
}

int Pop(Stk &s, int i, int &x)
{
    if(i<0 || i>1)
        return 0;
    switch(i)
    {
    case 0:
        if(s.top[0] == -1)
            return 0;
        x = s.data[s.top[0]--];
        break;
    case 1:
        if(s.top[2] == maxnsize)
            return 0;
        x = s.data[s.top[1]++];
        break;
    }
    return 1;
}

int main()
{
    ios::sync_with_stdio(false);
    return 0;
}