rename repo, subdir for yearly challenges

2020/day01/ex2-c.c

@@ -0,0 +1,31 @@
+/* ex2-c:c: Advent2020 game, day 1/game 2
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(ac, av)
+char **av;
+{
+     int numbers[1000];         /* should do differently :
+                                 * either read twice, either create list
+                                 */
+     int n=0, i, j, k, n1, n2, n3;
+
+     while (scanf("%d", numbers+n) != EOF)
+          n++;
+     for (i=0; i<n; ++i) {
+          n1=numbers[i];
+          for (j=i+1; j<n; ++j) {
+               n2=numbers[j];
+               for (k=j+1; k<n; ++k) {
+                    n3=numbers[k];
+                    if (n1+n2+n3 == 2020) {
+                         printf("%s : %d:%d %d:%d %d:%d sum=%d mul=%d\n", *av,
+                                i, n1, j, n2, k, n3, n1+n2+n3, n1*n2*n3);
+                         exit (0);
+                    }
+               }
+          }
+     }
+}