40分求助

#include <cctype>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <algorithm>
#include <bitset>
#include <complex>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <map>
#include <new>
#include <queue>
#include <set>
#include <stack>

#if __cplusplus >= 201103L
#include <chrono>
#include <random>
#include <thread>
#include <tuple>
#endif

#define ll long long
#define sll static long long
#define db double
#define sint static int
#define lint inline int
#define lb inline bool
#define lll inline long long
#define For(i, bg, ed,add) for (int i = bg; i <= ed; i += add)
#define whileTrue wltu while (true)
#define elif else if

using namespace std;
string Pas;//原密串 
string Nxpas;//需解密密串 
map<char, char> book;//标记数组
int flag1 = 1;
int main() {//先判断Failed 
	cin >> Pas;
	for (char i = 'A'; i <= 'Z'; i++) book[i] = ' ';
	for (int i = 0; i < Pas.length(); i++) {
		char s;
		cin >> s;
		if (book[s] == ' ' or book[s] == Pas[i]) {
			book[s] = Pas[i];
		} else {
			flag1 = 0;
			break;
		}
	}
	cin >> Nxpas;
	for (char i = 'A'; i <= 'Z'; i++) {
		if (book[i] == ' ') {
			flag1 = 0;
		}
	}
	if (!flag1) {
		cout << "Failed";
	} else {
		for (int i = 0; i < Nxpas.size(); i++) {
			cout << book[Nxpas[i]];
		}
	}
	cout << endl;
	return 0;
}