poj 3295 Tautology

#include <iostream>
#include <stack>
using namespace std;

const int MAX_N = 1000 + 10;
char A[MAX_N];

int p, q, r, s, t, ans;

int Match( char x )
{
    int value = 0;

    switch(x)
    {
        case ‘0‘:value = 0; break;
        case ‘1‘:value = 1; break;
        case ‘p‘:value = p;break;
        case ‘q‘:value = q;break;
        case ‘r‘:value = r;break;
        case ‘s‘:value = s;break;
        case ‘t‘:value = t;break;
        default: value = p;
    }

    return value;
}

int Calc( char a, char b, char T )
{
    int x, y, ans;

    x = Match( a );
    y = Match( b );
    switch( T )
    {
        case ‘K‘:ans = x && y;break;
        case ‘A‘:ans = x||y;break;
        case ‘N‘:ans = !x;break;
        case ‘C‘:ans = (!x)||y;break;
        case ‘E‘:ans = (x == y);break;
    }
    return ans;
}


int WWF( )
{
    int Rusult = 0;
    int Len = strlen( A );
    stack<char>SL, SR;

    for ( p = 0; p <= 1; ++p )
        for( q = 0; q <= 1; ++q )
            for( r = 0; r <= 1; ++r )
                for( s = 0; s <=1; ++s )
                    for( t = 0; t <= 1; ++t ){

        for ( int i = 0; i < Len; ++i )
                SL.push( A[i] );

            while ( !SL.empty() )
            {
                char x, y, T;
                int flag = 0;

                T = SL.top();SL.pop();

                switch(T)
                {
                    case ‘p‘:
                    case ‘q‘:
                    case ‘r‘:
                    case ‘s‘:
                    case ‘t‘: SR.push(T);flag = 1;break;
                }

                if ( flag == 1 )
                    continue;
                else
                if ( T == ‘N‘ )
                {
                    x = SR.top();SR.pop();
                    ans = Calc( x, x, T );
                }
                else
                {
                    x = SR.top();SR.pop();
                    y = SR.top();SR.pop();
                    ans = Calc( x, y, T );
                }

                SR.push( ans + ‘0‘ );
            }

            if ( ans == 0 )
                return 0;
        }

    return 1;
}


int main()
{
    int flag = 0;

    while ( scanf( "%s", A ) != EOF )
    {
        if ( A[0] == ‘0‘ )
            break;

        flag = WWF();

        if ( flag == 0 )
            printf( "not\n" );
        else
            printf( "tautology\n" );
    }

    return 0;
}