FJ string [string simulation]

FJ string

Description

FJ wrote some strings on the sand table: A1 = "A" A2 = "ABA" A3 = "ABACABA" A4 = "ABACABADABACABA"…… Can you find the pattern and write all the series AN?

Input

There is only one number: N ≤ 26.

Output

Please output the corresponding string AN, ending with a newline character. The output must not contain extra spaces, line feeds, or carriage returns.

Sample Input 1 

3

Sample Output 1

Flats

 Analysis: get new skills, convert char to string.

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

int main()
{
    int n;
    scanf("%d", &n);
    string st = "";
    for(int i = 1; i <= n; i ++)
    {
        string tp = st;
        char  xx = (char)((int)'A' + i - 1);
        string str;
        stringstream stream;
        stream << xx;
        str = stream.str();
        st += str;
        st += tp;
    }
    cout << st << endl;
    return 0;
}