rename repo, subdir for yearly challenges

2020/day12/ex1-c.c

@@ -0,0 +1,61 @@
+/* ex1-c: Advent2020 game, day 12/game 1
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define ABS(i)	((i)>=0?(i):(-i))
+
+int main(ac, av)
+    int ac;
+    char **av;
+{
+    char line[512], command;
+    unsigned val, direction=90, real;
+    int x=0, y=0;
+
+    while (fgets(line, sizeof line, stdin)) {
+        command=*line;
+        val=atoi(line+1);
+        switch (command) {
+            case 'N':
+                real=0;
+                break;
+            case 'E':
+                real=90;
+                break;
+            case 'S':
+                real=180;
+                break;
+            case 'W':
+                real=270;
+                break;
+            case 'F':
+                real=direction;
+                break;
+            case 'L':
+                val=360-val;
+            case 'R':
+                direction=(direction+val)%360;
+        }
+        if (command != 'R' && command != 'L') {
+            switch (real) {
+                case 0:
+                    y+=val;
+                    break;
+                case 90:
+                    x+=val;
+                    break;
+                case 180:
+                    y-=val;
+                    break;
+                case 270:
+                    x-=val;
+                    break;
+            }
+        }
+    }
+    printf("%s : res=%d\n", *av, ABS(x)+ABS(y));
+    exit (0);
+}