我想创建一个随机字符串,由字母-数字字符组成。我希望能够指定字符串的长度。
如何在c++中做到这一点?
我想创建一个随机字符串,由字母-数字字符组成。我希望能够指定字符串的长度。
如何在c++中做到这一点?
当前回答
#include <iostream>
#include <string>
#include <random>
std::string generateRandomId(size_t length = 0)
{
static const std::string allowed_chars {"123456789BCDFGHJKLMNPQRSTVWXZbcdfghjklmnpqrstvwxz"};
static thread_local std::default_random_engine randomEngine(std::random_device{}());
static thread_local std::uniform_int_distribution<int> randomDistribution(0, allowed_chars.size() - 1);
std::string id(length ? length : 32, '\0');
for (std::string::value_type& c : id) {
c = allowed_chars[randomDistribution(randomEngine)];
}
return id;
}
int main()
{
std::cout << generateRandomId() << std::endl;
}
其他回答
我的2p解:
#include <random>
#include <string>
std::string random_string(std::string::size_type length)
{
static auto& chrs = "0123456789"
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ";
thread_local static std::mt19937 rg{std::random_device{}()};
thread_local static std::uniform_int_distribution<std::string::size_type> pick(0, sizeof(chrs) - 2);
std::string s;
s.reserve(length);
while(length--)
s += chrs[pick(rg)];
return s;
}
我希望这能帮助到一些人。
在https://www.codechef.com/ide上用c++ 4.9.2测试
#include <iostream>
#include <string>
#include <stdlib.h> /* srand, rand */
using namespace std;
string RandomString(int len)
{
string str = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
string newstr;
int pos;
while(newstr.size() != len) {
pos = ((rand() % (str.size() - 1)));
newstr += str.substr(pos,1);
}
return newstr;
}
int main()
{
srand(time(0));
string random_str = RandomString(100);
cout << "random_str : " << random_str << endl;
}
输出: random_str: DNAT1LAmbJYO0GvVo4LGqYpNcyK3eZ6t0IN3dYpHtRfwheSYipoZOf04gK7OwFIwXg2BHsSBMB84rceaTTCtBC0uZ8JWPdVxKXBd
随机字符串,每个运行文件=不同的字符串
auto randchar = []() -> char
{
const char charset[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz";
const size_t max_index = (sizeof(charset) - 1);
return charset[randomGenerator(0, max_index)];
};
std::string custom_string;
size_t LENGTH_NAME = 6 // length of name
generate_n(custom_string.begin(), LENGTH_NAME, randchar);
void gen_random(char *s, size_t len) {
for (size_t i = 0; i < len; ++i) {
int randomChar = rand()%(26+26+10);
if (randomChar < 26)
s[i] = 'a' + randomChar;
else if (randomChar < 26+26)
s[i] = 'A' + randomChar - 26;
else
s[i] = '0' + randomChar - 26 - 26;
}
s[len] = 0;
}
一些更简单和更基本的东西,如果你想让你的字符串包含任何可打印的字符:
#include <time.h> // we'll use time for the seed
#include <string.h> // this is for strcpy
void randomString(int size, char* output) // pass the destination size and the destination itself
{
srand(time(NULL)); // seed with time
char src[size];
size = rand() % size; // this randomises the size (optional)
src[size] = '\0'; // start with the end of the string...
// ...and work your way backwards
while(--size > -1)
src[size] = (rand() % 94) + 32; // generate a string ranging from the space character to ~ (tilde)
strcpy(output, src); // store the random string
}