编译没问题，运行时 打印“已放弃”是怎么回事~

#include<iostream>
#include<string>
using namespace std;
int main(void)
{
        int flag = 0;
        string str("XiaoYaoKe");
        string::iterator ite = str.begin();
        while(ite != str.end())
        {
                if(isupper(*ite))
                {
                        if(!flag)    //第一个大写字母不作处理
                                flag = 1;
                        else
                                str.insert(ite, ' ');
                }
                ite++;
        }
        cout << str << endl;
        return 0;
}