题目（15）答案

#include <iostream>
#include <string>

using namespace std;

int main()
{
	string s;
	getline(cin, s);
	int length = s.size();
	for(int i = 0; i < length; i++)
	{
		char m = s[i];
		if(m >= 'F' && m <= 'Z')
			m = m - 5, s[i] = m;
		else if(m == 'E')
			m = 'Z', s[i] = m;
		else if(m == 'D')
			m = 'Y', s[i] = m;
		else if(m == 'C')
			m = 'X', s[i] = m;
		else if(m == 'B')
			m = 'W', s[i] = m;
		else if(m == 'A')
			m = 'V', s[i] = m;
			
	} 
	cout << s << endl;
	return 0;
}

连续的if就可以