python/TangDou/CSP-J/J2-2022/expr_4_QiuZhi_LuoJi_JianHuaVersion.cpp

#include <bits/stdc++.h>
using namespace std;

/*
0&(1|0)|(1|1|1&0)
答案：1

(0|1&0|1|1|(1|1))&(0&1&(1|0)|0|1|0)&0
答案：0
*/
unordered_map<char, int> h{{'|', 1}, {'&', 2}};
stack<int> num;
stack<char> op;

void eval() {
    int a = num.top();
    num.pop();

    int b = num.top();
    num.pop();

    char p = op.top();
    op.pop();

    int r;
    if (p == '|')
        r = b | a;
    else if (p == '&')
        r = b & a;
    num.push(r);
}

int main() {
    string s;
    cin >> s;
    for (int i = 0; i < s.size(); i++) {
        if (isdigit(s[i]))
            num.push(s[i] - '0');
        else if (s[i] == '(')
            op.push(s[i]);
        else if (s[i] == ')') {
            while (op.top() != '(') eval();
            op.pop();
        } else {
            while (op.size() && h[op.top()] >= h[s[i]]) eval();
            op.push(s[i]);
        }
    }
    while (op.size()) eval();

    printf("%d\n", num.top());
    return 0;
}