по первой ссылке в гугле

C++:





[CODE]
std
::
string
random_string
(
size_t length
)
{
auto
randchar
=
[
]
(
)
->
char
{
const
char
chars
[
]
=
"0123456789"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
;
const
size_t max_index
=
(
sizeof
(
chars
)
-
1
)
;
return
chars
[
rand
(
)
%
max_index
]
;
}
;
std
::
string
str
(
length
,
0
)
;
std
::
generate_n
(
str
.
begin
(
)
,
length
,
randchar
)
;
return
str
;
}
int
main
(
)
{
std
::
cout