ISEC 2010 level8 random array

ISEC 2010 prequal 8번이었나 random array 로 bruteforce 하는  문제 .
난수 반복 때문에 한참 헤메다가 cpu 클럭으로 생성하게 함.

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#include <stdio.h> #include <stdlib.h> #include <time.h> #include <string.h> #include <unistd.h> #include <sys/types.h>     #define RAN_SIZE   28 #define TRUE        1 #define RESULT      "result"   int main(void) {     char buf[28] = { };     char tmp[28] = { };     char last[28] = {};       char x[16] = { };     char y[16] = { };       char str[32] = "6445666F485F6CF526CC5457F3A4";       int rand_num = 0;     int len = 0;     int count;     int status = 0;     int flag = 0;     int i;       FILE *fp;       pid_t pid;     clockid_t clock_id;     long ret;     char ptr = NULL;     struct timespec t;       pid = getpid();         fp = fopen(RESULT, "a+");     memcpy(buf,str,28);       while(TRUE) {           //get cpu clock         clock_getcpuclockid(pid, &clock_id);         clock_gettime(clock_id, &t);           srand(t.tv_nsec);           //shuffling the array           do {             rand_num = rand() % RAN_SIZE;             count = 0;             if (len <= 0)                 goto LABEL_1;             do {                 if (tmp[count] == rand_num) {                     status = 1;                 }                 ++count;             } while (count < len);               if (status) {                 status = 0;             }             else { LABEL_1:                 tmp[len++] = rand_num;             }                 } while (len < 28);         // is it printable?         for (i = 0; i < len; i=i+2) {             sprintf(x,"%c%c",buf[tmp[i]],buf[tmp[i+1]]);             ret = strtol(x,&ptr,16);             sprintf(y,"%c",ret);             if (( *y < 0x1f) || (*y > 0x7e)) {                 flag = 1;                 break;             }             strcat(last,y);         }                   if (!flag) {             fprintf(fp,"%s\n",last);         }           status = 0;         len = 0;         count = 0;         rand_num = 0;         flag = 0;         memset(x,0x00,sizeof(x));         memset(y,0x00,sizeof(y));         memset(last,0x00,sizeof(last));     }     fclose(fp);     return 0; }

Python 으로는 아래처럼 random.shuffle 로 돌리면 된다.

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import random, re   s = '6445666F485F6C5F6C2C54573F4A'   ran = [] for x in range(28):     ran.append(str(x))   random.shuffle(ran)