UVA 11988 Broken Keyboard (a.k.a. Beiju Text) STL

#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <iterator>
using namespace std;

deque<string> dq;

int main() {
    string str;
    while( cin >> str ) {
        dq.clear();
        string temp = "";
        int len = (int)str.length();
        int flag = 1; // 记录当前状态 0 （光标开头）1（光标末尾）
        int i = 0;
        
        while(1) {
            if( i >= len ) break;
            while( i < len && str[i] != ‘[‘ && str[i] != ‘]‘ ) {
                temp += str[i];
                i++;
            }
            
            if( flag == 0 ) {
                dq.push_front(temp);
            }
            else {
                dq.push_back(temp);
            }
            temp = "";
            if( str[i] == ‘[‘ ) {
                flag = 0;
                i++;
            }
            else {
                flag = 1;
                i++;
            }
        }
        deque<string>::iterator it;
        for( it = dq.begin(); it != dq.end(); it++ ) {
            cout << *it;
        }
        cout << endl;
    }
    return 0;
}