UVA

题意
模拟二进制数字的位运算

思路
手写 位运算函数
要注意几个坑点
一元运算符的优先级 大于 二元
一元运算符 运算的时候 要取消前导0
二元运算符 运算的时候 要将两个数字 数位补齐
输出的时候 也要 注意 要取消前导0

特别要注意
如果输入的算式 只有一个数字
那么要将 这个数字的前导0 取消 再输出

AC代码

#include <cstdio>
#include <cstring>
#include <ctype.h>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <deque>
#include <vector>
#include <queue>
#include <string>
#include <map>
#include <stack>
#include <set>
#include <numeric>
#include <sstream>
#include <iomanip>
#include <limits>

#define CLR(a) memset(a, 0, sizeof(a))
#define pb push_back

using namespace std;
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef pair<string, int> psi;
typedef pair<string, string> pss;

const double PI = acos(-1.0);
const double E = exp(1.0);
const double eps = 1e-30;

const int INF = 0x3f3f3f3f;
const int maxn = 4e5 + 5;
const int MOD = 1e9 + 7;

string Not(string s)
{
    while (s.size() > 1 && s[0] == '0')
        s.erase(0, 1);
    int len = s.size();
    map <char, char> m;
    m['0'] = '1';
    m['1'] = '0';
    string ans = "";
    for (int i = 0; i < len; i++)
        ans += m[s[i]];
    while (ans.size() > 1 && ans[0] == '0')
        ans.erase(0, 1);
    return ans;
}

string Shr (string s)
{
    while (s.size() > 1 && s[0] == '0')
        s.erase(0, 1);
    string ans = s;
    if (ans.size() == 1)
        return "0";
    if (ans.size() > 1)
        ans.erase(ans.size() - 1, 1);
    while (ans.size() > 1 && ans[0] == '0')
        ans.erase(0, 1);
    return ans;
}

string Shl (string s)
{
    while (s.size() > 1 && s[0] == '0')
        s.erase(0, 1);
    string ans = s;
    ans.insert(ans.size(), "0");
    while (ans.size() > 1 && ans[0] == '0')
        ans.erase(0, 1);
    return ans;
}

string Xor (string x, string y)
{
    string ans = "";
    while (x.size() < y.size())
        x.insert(0, "0");
    while (x.size() > y.size())
        y.insert(0, "0");
    int len = x.size();
    for (int i = 0; i < len; i++)
    {
        if (x[i] != y[i])
            ans += "1";
        else 
            ans += "0";
    }
    while (ans.size() > 1 && ans[0] == '0')
        ans.erase(0, 1);
    return ans;
}

string And (string x, string y)
{
    string ans = "";
    while (x.size() < y.size())
        x.insert(0, "0");
    while (x.size() > y.size())
        y.insert(0, "0");
    int len = x.size();
    for (int i = 0; i < len; i++)
    {
        if (x[i] == '0' || y[i] == '0')
            ans += '0';
        else
            ans += '1';
    }
    while (ans.size() > 1 && ans[0] == '0')
        ans.erase(0, 1);
    return ans;
}

string Or(string x, string y)
{
    string ans = "";
    while (x.size() < y.size())
        x.insert(0, "0");
    while (x.size() > y.size())
        y.insert(0, "0");
    int len = x.size();
    for (int i = 0; i < len; i++)
    {
        if (x[i] == '1' || y[i] == '1')
            ans += '1';
        else
            ans += '0';
    }
    while (ans.size() > 1 && ans[0] == '0')
        ans.erase(0, 1);
    return ans;
}

int main()
{
    int t;
    cin >> t;
    getchar();
    int count = 1;
    while (t--)
    {
        string s;
        getline(cin, s);
        stack <string> code;
        stack <string> num;
        string temp = "";
        int len = s.size();
        for (int i = 0; i <= len; i++)
        {
            if (i < len && s[i] != ' ')
                temp += s[i];
            else
            {
                if (isdigit(temp[0]))
                {
                    string n = temp;
                    num.push(n);
                    if (num.size() >= 1)
                    {
                        n = num.top();
                        num.pop();
                        string s = " ";
                        if (!code.empty())
                            s = code.top();
                        while (s == "not" || s == "shr" || s == "shl")
                        {
                            code.pop();
                            if (s == "not")
                                n = Not(n);
                            else if (s == "shr")
                                n = Shr(n);
                            else if (s == "shl")
                                n = Shl(n);
                            if (!code.empty())
                                s = code.top();
                            else
                                s = " ";
                        }
                        num.push(n);
                    }
                    if (num.size() >= 2)
                    {
                        string s = " ";
                        if (!code.empty())
                            s = code.top();
                        while ((s == "xor" || s == "and" || s == "or") && num.size() >= 2)
                        {
                            code.pop();
                            string x = num.top();
                            num.pop();
                            string y = num.top();
                            num.pop();
                            string ans;
                            if (s == "xor")
                                ans = Xor(x, y);
                            else if (s == "and")
                                ans = And(x, y);
                            else if (s == "or")
                                ans = Or(x, y);
                            if (!code.empty())
                                s = code.top();
                            else
                                s = " ";
                            num.push(ans);
                        }
                    }
                }
                else
                {
                    code.push(temp);
                }
                temp.clear();
            }
        }
        string ans = num.top();
        while (ans.size() > 1 && ans[0] == '0')
            ans.erase(0, 1);
        printf("Case %d: ", count++);
        cout << ans << endl;
    }
}