random seed

#include <iostream>
using namespace std;

int main(int argc, char** argv)
{
    // cout << "You have entered " << argc << " arguments:" << "\n";
    // for (int i = 0; i < argc; ++i) {
    //     cout << argv[i] << "\n";
    // }
 
    const char *seed = argv[1];
    srand(*seed);
    cout << "seed " << seed << endl;

    int answer;
    for (int i = 0; i < 10; i++) {
        answer = rand() % 100;
        cout << answer << endl;
    }
    
    return 0;
}

실행

$ ./rand_seed 1
seed 1
43
19
38
8
48
58
62
71
76
26
$ ./rand_seed 1
seed 1
43
19
38
8
48
58
62
71
76
26

$ ./rand_seed 2
seed 2
50
68
11
66
78
30
6
49
99
88
$ ./rand_seed 2
seed 2
50
68
11
66
78
30
6
49
99
88

동일한 seed 값에서는 동일한 램덤 패턴으로 랜덤 값이 생성된다.