2016/advent3.c

   1 #define _GNU_SOURCE 1
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include <stdbool.h>
   7
   8 bool check (int s1, int s2, int s3)
   9 {
  10   int t;
  11   if (s1 > s2) {
  12     t = s1;
  13     s1 = s2;
  14     s2 = t;
  15   }
  16   if (s2 > s3) {
  17     t = s2;
  18     s2 = s3;
  19     s3 = t;
  20   }
  21   return s1 + s2 > s3;
  22 }
  23
  24 int main(void)
  25 {
  26   int count = 0;
  27   int s[9];
  28   while (scanf (" %d %d %d\n %d %d %d\n %d %d %d\n", &s[0], &s[1], &s[2], &s[3],
  29                 &s[4], &s[5], &s[6], &s[7], &s[8]) == 9) {
  30     if (check (s[0], s[3], s[6]))
  31       count++;
  32     if (check (s[1], s[4], s[7]))
  33       count++;
  34     if (check (s[2], s[5], s[8]))
  35       count++;
  36   }
  37   printf ("found %d possible triangles\n", count);
  38   return 0;
  39 }