21a.c

   1 #include <stdio.h>
   2
   3 void move (int roll, int *p, int *score)
   4 {
   5         *p = (*p+roll*9+6)%10;
   6         if (*p == 0)
   7                 *p = 10;
   8         *score += *p;
   9 }
  10
  11 int main()
  12 {
  13         int p1, p2, p1score = 0, p2score = 0;
  14         if (2 != scanf(
  15                         "Player 1 starting position: %d\n"
  16                         "Player 2 starting position: %d\n", &p1, &p2))
  17                 return 1;
  18
  19         int roll = 0;
  20         while (p1score < 1000 && p2score < 1000) {
  21                 if (roll%2==0)
  22                         move(roll, &p1, &p1score);
  23                 else
  24                         move(roll, &p2, &p2score);
  25                 roll++;
  26         }
  27         printf("%d\n", (roll%2==0 ? p1score : p2score)*roll*3);
  28 }