poj 3295 Tautology

http://poj.org/problem?id=3295

代码：

#include<iostream>

#include<stdio.h>

#include<string.h>

#include<math.h>

#include<algorithm>

#include<vector>

#include<set>

#include<map>

#include<string>

#include<queue>

#include<stack>

#include <iomanip>

using namespace std;

#define LL long long

#define sint short int

const int INF=0x3f3f3f3f;

//priority_queue<int,vector<int>,greater<int> >qt;

bool a[7];

bool ans;

string s;

bool K(char k,bool t1)

{

    return (!t1);

}

bool K(char k,bool t1,bool t2)

{

    if(k=='K')

    return (t1&&t2);

    if(k=='A')

    return (t1||t2);

    if(k=='C')

    return ((!t1)||t2);

    if(k=='E')

    return (t1==t2);

    return true;

}

void test()

{

    stack<bool>st;

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

    {

        if(s[i]<='t'&&s[i]>='p')

        st.push(a[s[i]-'p']);

        else

        {

            bool tmp1,tmp2;

            if(s[i]=='N')

            {

                tmp1=st.top();st.pop();

                st.push(K(s[i],tmp1));

            }else

            {

                tmp1=st.top();st.pop();

                tmp2=st.top();st.pop();

                st.push(K(s[i],tmp1,tmp2));

            }

        }

    }

    if(st.top()==false)

    ans=st.top();

}

void dfs(int x)

{

    if(x==5)

    {test();return ;}

    a[x]=true;

    dfs(x+1);

    a[x]=false;

    dfs(x+1);

    if(ans==false)

    return ;

}

int main()

{

    //freopen("data.in","r",stdin);

    while(cin>>s)

    {

        if(s=="0")

        break;

        ans=true;

        dfs(0);

        if(ans)

        cout<<"tautology"<<endl;

        else

        cout<<"not"<<endl;

    }

    return 0;

}