tools/bselect.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 static unsigned char *ptr[100];
   5 static int ptrc;
   6
   7 #define M 256
   8
   9 static struct
  10 {
  11         int pos;
  12         int cnt;
  13 } max[M];
  14
  15
  16 static int active[100];
  17 static int activec;
  18
  19 static int active_pos;
  20
  21 static void
  22 fill_max(void)
  23 {
  24         int i, n, b, c, u;
  25
  26
  27         memset(max, 0, sizeof(max));
  28
  29         for (b = 0; b < 0x800; b++)
  30         {
  31                 c = 0;
  32                 for (i = 0; i < activec; i++)
  33                 {
  34                         for (u = i + 1; u < activec; u++)
  35                         {
  36                                 if (ptr[active[i]][b] == ptr[active[u]][b])
  37                                 {
  38                                         goto bad;
  39                                 }
  40                         }
  41                         c ++;
  42 bad:;
  43                 }
  44
  45                 for (i = 0; i < M; i ++)
  46                 {
  47                         if (max[i].cnt < c)
  48                         {
  49                                 max[i].pos = b;
  50                                 max[i].cnt = c;
  51                                 break;
  52                         }
  53                 }
  54         }
  55 }
  56
  57 static void
  58 select_max(void)
  59 {
  60         int i, m, c;
  61
  62         m = max[0].cnt;
  63
  64         if (max[0].cnt == 1)
  65         {
  66                 printf("no solution!\n");
  67                 exit(1);
  68         }
  69         c = 0;
  70         for (i = 0; i < M; i++)
  71         {
  72                 if (m == max[i].cnt)
  73                 {
  74                         c++;
  75                 }
  76         }
  77
  78         i = random() % c;
  79         active_pos = max[i].pos;
  80         printf("0x%03X (%d) ", active_pos, max[i].cnt);
  81 }
  82
  83
  84 static void
  85 search_active(void)
  86 {
  87         int i, j, a;
  88         int tmpa[100];
  89
  90
  91         a = 0;
  92         for (i = 0; i < activec; i++)
  93         {
  94                 for (j = 0; j < activec; j++)
  95                 {
  96                         if (i == j)
  97                         {
  98                                 continue;
  99                         }
 100                         if (ptr[active[i]][active_pos] ==
 101                                 ptr[active[j]][active_pos])
 102                         {
 103                                 tmpa[a] = active[i];
 104                                 a++;
 105                                 break;
 106                         }
 107                 }
 108         }
 109
 110         printf("(%d) ", a);
 111         for (i = 0; i < activec; i++)
 112         {
 113                 printf("%02X ", ptr[active[i]][active_pos]);
 114         }
 115
 116         printf("\n");
 117
 118         memcpy(active, tmpa, sizeof(active));
 119         activec = a;
 120 }
 121
 122 int
 123 main(int argc, char *argv[])
 124 {
 125         int i, u, b, c;
 126         FILE *f;
 127
 128
 129         srandom(time(NULL));
 130
 131         ptrc = argc - 1;
 132
 133         /*
 134          * read data
 135          */
 136
 137         for (i = 0; i < ptrc; i++)
 138         {
 139                 ptr[i] = malloc(0x800);
 140                 f = fopen(argv[i + 1], "rb");
 141                 fread(ptr[i], 1, 0x800, f);
 142                 fclose(f);
 143                 active[i] = i;
 144         }
 145         activec = ptrc;
 146
 147         while (activec > 0)
 148         {
 149                 fill_max();
 150                 select_max();
 151                 search_active();
 152         }
 153
 154         return 0;
 155 }
 156