random string c 2b 2b

1#include <string>
2
3string  gen_random(int len) {
4    string s;
5    static const char alphanum[] =
6        "0123456789"
7        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
8        "abcdefghijklmnopqrstuvwxyz";
9
10    for (int i = 0; i < len; ++i) {
11        s += alphanum[rand() % (sizeof(alphanum) - 1)];
12    }
13
14    return s;
15}

1 
2string  gen_random(int len) {
3        string s;
4        static const char alphanum[] =
5            "0123456789"
6            "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
7            "abcdefghijklmnopqrstuvwxyz";
8
9        for (int i = 0; i < len; ++i) {
10            s+= alphanum[rand() % (sizeof(alphanum) - 1)];
11             }
12
13     return s;
14