Decrypt/Decrypt/genpwd.cpp

   1 #include <stdio.h>
   2 #include <string.h>
   3
   4 const char ch[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
   5
   6 char(*genpwd())[16]
   7 {
   8         // length of password
   9         static int length = 5;
  10
  11         static char (*arrpwd)[16] = NULL;
  12         static int arrindex[15] = {0};
  13         arrindex[length-1] = -1;
  14
  15         if(arrpwd == NULL) {
  16                 arrpwd = new char[100000][16];
  17                 memset(arrpwd,0,100000*16);
  18         } else {
  19                 memset(arrpwd,0,100000*16);
  20         }
  21
  22         int chlen = strlen(ch);
  23         static int breakflg = 0;
  24
  25         if(breakflg==1) {
  26                 delete[] arrpwd;
  27                 return NULL;
  28         }
  29
  30         for(int cur=0;cur<100000 && breakflg==0;cur++) {
  31                 for(;;){
  32                         if (breakflg) goto RETURN;
  33                         //add
  34                         for(int i=length-1,plus=1;i>=0;i--) {
  35                                 if(plus==1) {
  36                                         if(++arrindex[i] == chlen) {
  37                                                 arrindex[i] = 0;
  38                                                 if (i==0) breakflg=1;
  39                                         } else {
  40                                                 break;
  41                                         }
  42                                 }
  43                         }
  44                         //check
  45                         int upperflag = 0, numflag = 0;
  46                         for(int i=1;i<length;i++) {
  47                                 if(arrindex[i]>=26 && arrindex[i]<=51) upperflag = 1;
  48                                 if(arrindex[i]>=52 && arrindex[i]<=61) numflag = 1;
  49                         }
  50                         if(upperflag && numflag) break;
  51
  52                 }
  53
  54                 //output
  55                 for(int i=length-1,plus=1;i>=0;i--) {
  56                         arrpwd[cur][i] = ch[arrindex[i]];
  57                 }
  58                 arrpwd[cur][length] = '\0';
  59         }
  60 RETURN:
  61         return arrpwd;
  62 }