cleanup part one and do part two

diff --git a/17a.c b/17a.c
index 2140026..903978e 100644 (file)
--- a/17a.c
+++ b/17a.c
@@ -1,21 +1,17 @@
 #include <stdio.h>
-#include <stdlib.h>
 #include <stdbool.h>
-#include <string.h>
 
 bool is_in(int dx, int dy, int x1, int x2, int y1, int y2, int *maxy)
 {
        int x = 0, y = 0, my = 0;
-       while (y >= y2 && x <= x2) {
+       while (y >= y1 && x <= x2) {
                x+=dx;
                y+=dy;
+               my = y > my ? y : my;
                dx = dx == 0 ? 0 : dx-1;
                dy--;
-               if (y > my)
-                       my = y;
-               if (x >= x1 && x <= x2 && y >= y1 && y <= y2)  {
-                       if (my > *maxy)
-                               *maxy = my;
+               if (x >= x1 && x <= x2 && y >= y1 && y <= y2) {
+                       *maxy = my > *maxy ? my : *maxy;
                        return true;
                }
        }
@@ -24,23 +20,8 @@ bool is_in(int dx, int dy, int x1, int x2, int y1, int y2, int *maxy)
 
 int main()
 {
-       size_t len;
-       char *buf = NULL;
-       if (getline(&buf, &len, stdin) == -1)
-               return 1;
-       printf("%s", buf);
-
-       while (*buf++ != '=');
-
-       int x1 = strtol(buf, &buf, 10);
-       buf+=strlen("..");
-       int x2 = strtol(buf, &buf, 10);
-       buf+=strlen(", y=");
-       int y1 = strtol(buf, &buf, 10);
-       buf+=strlen("..");
-       int y2 = strtol(buf, &buf, 10);
-
-       int maxy = 0;
+       int x1, x2, y1, y2, maxy = 0;
+       scanf("target area: x=%d..%d, y=%d..%d\n", &x1, &x2, &y1, &y2);
        for (int dy = x2; dy >= 0; dy--)
                for (int dx = 1; dx <= x2; dx++)
                        if (is_in(dx, dy, x1, x2, y1, y2, &maxy))

diff --git a/17b.c b/17b.c
new file mode 100644 (file)
index 0000000..a90c27f
--- /dev/null
+++ b/17b.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+#include <stdbool.h>
+
+bool is_in(int dx, int dy, int x1, int x2, int y1, int y2)
+{
+       int x = 0, y = 0;
+       while (y >= y1 && x <= x2) {
+               x+=dx;
+               y+=dy;
+               dx = dx == 0 ? 0 : dx-1;
+               dy--;
+               if (x >= x1 && x <= x2 && y >= y1 && y <= y2)
+                       return true;
+       }
+       return false;
+}
+
+int main()
+{
+       int x1, x2, y1, y2, n = 0;
+       scanf("target area: x=%d..%d, y=%d..%d\n", &x1, &x2, &y1, &y2);
+       for (int dy = x2; dy >= y1; dy--)
+               for (int dx = 0; dx <= x2; dx++)
+                       if (is_in(dx, dy, x1, x2, y1, y2))
+                               n++;
+       printf("%d\n", n);
+}