题解 | Counterfeit Dollar

#include <iostream>
#include <cstring>
#include <algorithm>
#include<string>
#include<map>
using namespace std;
map<char, bool>heavy, light, equall, besides;
int main()
{
    for (int i = 0; i < 3; i++) {
        string str1, str2, op;
        cin >> str1 >> str2 >> op;
        if (op == "even") {
            for (int i = 0; i < str1.size(); i++)
                equall[str1[i]] = true, equall[str2[i]] = true;
        }
        if (op == "down") {
            besides.clear();
            for (int i = 0; i < str1.size(); i++) {
                heavy[str2[i]] = true; light[str1[i]] = true;
                besides[str1[i]] = true; besides[str2[i]] = true;
            }
            for (int i = 0; i < 12; i++) {
                if (besides.count('A' + i))continue;
                equall['A' + i] = true;
            }
        }
        if (op == "up") {
            besides.clear();
            for (int i = 0; i < str1.size(); i++) {
                heavy[str1[i]] = true; light[str2[i]] = true;
                besides[str1[i]] = true; besides[str2[i]] = true;
            }
            for (int i = 0; i < 12; i++) {
                if (besides.count('A' + i))continue;
                equall['A' + i] = true;
            }
        }
    }
    //最后排查剩下的就是假币
    for (int i = 0; i < 12; i++) {
        if (equall.count('A' + i))continue;
        //if (besides.count('A' + i))continue;
        
        if (heavy.count('A' + i) && light.count('A' + i))continue;
        //一会重一会轻也是z真币
        if (heavy.count('A' + i))
            printf("%c is the counterfeit coin and it is heavy.", 'A' + i);
        else
            printf("%c is the counterfeit coin and it is light.", 'A' + i);
    }
}