fixup

6 files changed, 123 insertions, 0 deletions

diff --git a/coding-exercises/2/44.rkt b/coding-exercises/2/44.rkt
index 9381ac9..3b8c76c 100644
--- a/coding-exercises/2/44.rkt
+++ b/coding-exercises/2/44.rkt
@@ -1,5 +1,6 @@
 #lang racket
 (require sicp-pict)
+(require "../../shared/pict.rkt")
 
 (define wave2 (beside einstein (flip-vert einstein)))
 (define wave4 (below wave2 wave2))
@@ -27,3 +28,11 @@
         (beside (below painter top-left)
                 (below bottom-right corner))))))
 (paint (corner-split einstein 4))
+
+(define (square-limit painter n)
+  (let ((quarter (corner-split painter n)))
+    (let ((half (beside (flip-horiz quarter) quarter)))
+      (below (flip-vert half) half))))
+
+(square-limit einstein 4)
+(paint (square-limit einstein 4))
diff --git a/coding-exercises/2/45.rkt b/coding-exercises/2/45.rkt
new file mode 100644
index 0000000..1939675
--- /dev/null
+++ b/coding-exercises/2/45.rkt
@@ -0,0 +1,10 @@
+#lang racket
+(require sicp-pict)
+
+(define (split adjoiner splitter)
+  (lambda (painter)
+    (let ((splitted (splitter painter painter)))
+      (adjoiner painter splitted))))
+
+(define right-split (split beside below))
+(define up-split (split below beside))
diff --git a/coding-exercises/2/46.rkt b/coding-exercises/2/46.rkt
new file mode 100644
index 0000000..4016ef7
--- /dev/null
+++ b/coding-exercises/2/46.rkt
@@ -0,0 +1,32 @@
+#lang racket
+(require "../../shared/lists.rkt")
+
+(define (make-vect x y)
+  (cons x y))
+(define (xcor-vect v)
+  (car v))
+(define (ycor-vect v)
+  (cdr v))
+
+(define (add-vect . v)
+  (make-vect 
+    (fold-right + 0 (map xcor-vect v))
+    (fold-right + 0 (map ycor-vect v))))
+(define (sub-vect . v)
+  (let ((xcors (map xcor-vect v))
+        (ycors (map ycor-vect v)))
+   (make-vect
+     (- (car xcors) (fold-right + 0 (cdr xcors)))
+     (- (car ycors) (fold-right + 0 (cdr ycors))))))
+(define (scale-vect s v)
+  (make-vect (* s (xcor-vect v))
+             (* s (ycor-vect v))))
+
+(define test-vec (make-vect 1 2))
+(define test-vec2 (make-vect 3 4))
+((lambda ()
+   (display (add-vect test-vec test-vec2))
+   (newline)
+   (display (sub-vect test-vec test-vec2))
+   (newline)
+   (display (scale-vect 3 test-vec))))
diff --git a/coding-exercises/2/47.rkt b/coding-exercises/2/47.rkt
new file mode 100644
index 0000000..5e1c562
--- /dev/null
+++ b/coding-exercises/2/47.rkt
@@ -0,0 +1,43 @@
+#lang racket
+(require "../../shared/pict.rkt")
+(define (make-frame origin edge1 edge2)
+  (list origin edge1 edge2))
+(define (origin-frame frame)
+  (car frame))
+(define (edge1-frame frame)
+  (cadr frame))
+(define (edge2-frame frame)
+  (caddr frame))
+
+(define test-frame (make-frame
+                     (make-vect 1 2)
+                     (make-vect 2 4)
+                     (make-vect 3 6)))
+((lambda ()
+   (newline)
+   (display test-frame)
+   (newline)
+   (display (origin-frame test-frame))
+   (display (edge1-frame test-frame))
+   (display (edge2-frame test-frame))))
+
+(define (make-frame2 origin edge1 edge2)
+  (cons origin (cons edge1 edge2)))
+(define (origin-frame2 frame)
+  (car frame))
+(define (edge1-frame2 frame)
+  (cadr frame))
+(define (edge2-frame2 frame)
+  (cddr frame))
+
+(define test-frame2 (make-frame2
+                      (make-vect 1 2)
+                      (make-vect 2 4)
+                      (make-vect 3 6)))
+((lambda ()
+   (newline)
+   (display test-frame2)
+   (newline)
+   (display (origin-frame2 test-frame2))
+   (display (edge1-frame2 test-frame2))
+   (display (edge2-frame2 test-frame2))))
diff --git a/coding-exercises/2/48.rkt b/coding-exercises/2/48.rkt
new file mode 100644
index 0000000..2ff696a
--- /dev/null
+++ b/coding-exercises/2/48.rkt
@@ -0,0 +1,8 @@
+#lang racket
+
+(define (make-segment start end)
+  (cons start end))
+(define (start-segment s)
+  (car s))
+(define (end-segment s)
+  (cdr s))
diff --git a/coding-exercises/2/49.rkt b/coding-exercises/2/49.rkt
new file mode 100644
index 0000000..688364a
--- /dev/null
+++ b/coding-exercises/2/49.rkt
@@ -0,0 +1,21 @@
+#lang racket
+(require (only-in sicp-pict 
+                  paint 
+                  segments->painter))
+(require "../../shared/pict.rkt")
+
+(define (outline frame)
+  (display frame)
+  (let ((corner 
+          (add-vect 
+            (edge1-frame frame)
+            (edge2-frame frame)))
+        (origin (origin-frame frame))
+        (e1 (edge1-frame frame))
+        (e2 (edge2-frame frame)))
+    (segments->painter 
+      (list (make-segment origin e1)
+            (make-segment e1 corner)
+            (make-segment corner e2)
+            (make-segment e2 origin)))))
+(paint outline)