#include <stdio.h>
#include <wchar.h>
#include <string.h>
#include <locale.h>
int main(int argc, char* argv[])
{
setlocale(LC_ALL,"Russian");
wchar_t str[256] = L"привет!!!";
wchar_t pchars[] = L"ауоыиэяюёе";
for (int i = 0; str[i] != '\0'; i++)
if (wcschr(pchars, str[i])) printf("%d ",i);
printf("\n");
return 0;
}