程序代码：

#include<iostream>
using namespace std;
char getchar(istream &in=cin )
{
    char ch;
    while (in.peek() != EOF && ((ch = in.get() == ' ') || ch == '\t'));
    return ch;
}
int main(void)
{
    char ch;
    double x;
    ch = getchar(cin);
    while (ch!='\n')
    {
        if ((ch >= '0')&&(ch <= '9'))
        {
            cin.putback(ch);
            cin >> x;
            cout << x << " ";
        }
        else
        {
            cout << "出现非法字符！" << endl;
            exit(1);
        }
        ch = getchar(cin);
    }
    cout << endl;
    system("pause");
    return 0;
}