POJ 2106 Boolean Expressions

标签：poj   c++   iostream   numbers   

Description

Input

Output

Sample Input

( V | V ) & F & ( F| V)
!V | V & V & !F & (F | V ) & (!F | F | !V & V)
(F&F|V|!V&!F&!(F|F&V))

Sample Output

Expression 1: F
Expression 2: V
Expression 3: V

Source

#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
int sum[110],poss;
int op[110],poso;
void insert(int t){
    while(poso&&op[poso-1]==3){
        t=!t;
        --poso;
    }
    sum[poss++]=t;
}
void calc(){
    int b=sum[--poss];
    int a=sum[--poss];
    int o=op[--poso];
    int c=(a&b);
    if(o==1)c=(a|b);
    insert(c);
}
int main(){
    int loop=1;
    char c;
    while((c=getchar())!=EOF){
        poss=poso=0;
        do{
            if(c=='('){
                op[poso++]=0;
            }else if(c==')'){
                while(poso&&op[poso-1]!=0)
                    calc();
                    --poso;
                insert(sum[--poss]);
            }else if(c=='!'){
                op[poso++]=3;
            }else if(c=='&'){
                while(poso&&op[poso-1]>=2)
                    calc();
                op[poso++]=2;
            }else if(c=='|'){
                while(poso&&op[poso-1]>=1)
                    calc();
                op[poso++]=1;
            }
            else if(c=='V'||c=='F'){
                insert(c=='V'?1:0);
            }
        }while((c=getchar())!='\n'&&c!=EOF);
        while(poso)calc();
        printf("Expression %d: %c\n",loop++,(sum[0]?'V':'F'));
    }
    return 0;
}

POJ 2106 Boolean Expressions

标签：poj   c++   iostream   numbers   

原文地址：http://blog.csdn.net/zp___waj/article/details/47725399