Solved exercices 1-34

.travis.yml

@@ -1,6 +1,6 @@
 language: clojure
-lein: lein2
-script: lein2 midje :config .midje-grading-config.clj
+lein: lein
+script: lein midje :config .midje-grading-config.clj
 jdk:
   - openjdk7
 notifications:

src/structured_data.clj

@@ -1,16 +1,17 @@
 (ns structured-data)
 
 (defn do-a-thing [x]
-  :-)
+  (let [twox (+ x x)]
+    (Math/pow twox twox)))
 
 (defn spiff [v]
-  :-)
+  (+ (first v)(get v 2)))
 
 (defn cutify [v]
-  :-)
+  (conj v "<3"))
 
 (defn spiff-destructuring [v]
-  :-)
+  (let [[x y z] v] (+ x z)))
 
 (defn point [x y]
   [x y])
@@ -19,96 +20,121 @@
   [bottom-left top-right])
 
 (defn width [rectangle]
-  :-)
+  (let [[[x1 y1] [x2 y2]] rectangle] 
+    (- x2 x1)))
 
 (defn height [rectangle]
-  :-)
+  (let [[[x1 y1] [x2 y2]] rectangle] 
+    (- y2 y1)))
 
 (defn square? [rectangle]
-  :-)
+  (= (height rectangle) (width rectangle)))
 
 (defn area [rectangle]
-  :-)
+  (* (height rectangle) (width rectangle)))
 
 (defn contains-point? [rectangle point]
-  :-)
+  (let [[[x1 y1] [x2 y2]] rectangle
+        [xp yp] point] 
+    (and (<= x1 xp x2) (<= y1 yp y2))))
+
 
 (defn contains-rectangle? [outer inner]
-  :-)
+  (let [[[xo1 yo1] [xo2 yo2]] outer
+        [[xi1 yi1] [xi2 yi2]] inner] 
+    (and (<= xo1 xi1 xi2 xo2) (<= yo1 yi1 yi2 yo2))))
 
 (defn title-length [book]
-  :-)
+  (count (:title book)))
 
 (defn author-count [book]
-  :-)
+  (count (:authors book)))
 
 (defn multiple-authors? [book]
-  :-)
+  (< 1 (author-count book)))
 
 (defn add-author [book new-author]
-  :-)
+  (assoc book :authors (conj (book :authors) new-author)))
+
 
 (defn alive? [author]
-  :-)
+  (nil? (get author :death-year)))
 
 (defn element-lengths [collection]
-  :-)
+  (map count collection))
 
 (defn second-elements [collection]
-  :-)
+  (map fnext collection))
 
 (defn titles [books]
-  :-)
+  (map :title books))
 
 (defn monotonic? [a-seq]
-  :-)
+  (or (apply <= a-seq) (apply >= a-seq)))
 
 (defn stars [n]
-  :-)
+  (apply str (repeat n "*")))
 
 (defn toggle [a-set elem]
-  :-)
+  (if (contains? a-set elem) 
+    (disj a-set elem)
+    (conj a-set elem)))
 
 (defn contains-duplicates? [a-seq]
-  :-)
+  (not (= (count a-seq) (count (set a-seq)))))
 
 (defn old-book->new-book [book]
-  :-)
+  (assoc book :authors (set (book :authors))))
 
 (defn has-author? [book author]
-  :-)
+  (contains? (book :authors) author))
 
 (defn authors [books]
-  :-)
+  (apply clojure.set/union (map :authors books)))
 
 (defn all-author-names [books]
-  :-)
+  (set (map :name (authors books))))
 
 (defn author->string [author]
-  :-)
+  (let [name (author :name) 
+        birth (author :birth-year) 
+        death (author :death-year)]
+    (str name 
+         (if birth (str " (" birth " - " death ")")))))
 
 (defn authors->string [authors]
-  :-)
+  (clojure.string/join ", " (map author->string authors)))
 
 (defn book->string [book]
-  :-)
+  (let [title (book :title) 
+        authors (authors->string (book :authors))]
+    (str title ", written by " authors)))
 
 (defn books->string [books]
-  :-)
+  (str 
+   (if (= (count books) 0) 
+     "No books." 
+     (str (count books) 
+          (if (= (count books) 1) 
+            (str " book. " 
+                 (str (apply book->string books)) ".")
+            (str " books. " 
+                 (clojure.string/join "" (map #(str (book->string %) ". ") books)))))))) 
+
 
 (defn books-by-author [author books]
-  :-)
+  (filter #(has-author? %  author) books))
 
 (defn author-by-name [name authors]
-  :-)
+  (first (filter #(= name (:name  %)) authors)))
 
 (defn living-authors [authors]
-  :-)
+  (filter alive? authors))
 
 (defn has-a-living-author? [book]
-  :-)
+  (not (empty? (living-authors (:authors book)))))
 
 (defn books-by-living-authors [books]
-  :-)
+  (filter has-a-living-author? books))
 
 ; %________%