直接模拟就好，这里利用了scanf不读空格的优势吧。。

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
using namespace std;

char st[100];
bool vis[300];

int main()
{
    //freopen("t.txt", "r", stdin);
    bool first = true;
    memset(vis, 0, sizeof(vis));
    vis['A'] = true;
    vis['E'] = true;
    vis['I'] = true;
    vis['O'] = true;
    vis['U'] = true;
    while (scanf("%s", st) != EOF)
    {
        int len = strlen(st);
        bool did = false;
        for (int i = 0; i < len; i++)
            if (!vis[st[i]])
            {
                if (st[i] <= 'Z' && st[i] >= 'A')
                    vis[st[i]] = true;
                if (!did)
                {
                    did = true;
                    if (st[i] <= 'Z' && st[i] >= 'A')
                    {
                        if (first)
                            first = false;
                        else
                            putchar(' ');
                    }
                }
                putchar(st[i]);
            }
    }
    putchar('\n');
    return 0;
}