adding a diff-by-n variation on the diff-by-one program

diff_by_n.py

@@ -0,0 +1,38 @@
+"""
+diff_by_n.py
+
+Donald Knuth
+Art of Computer Programming 
+Volume 4 Facsimile 0
+Variation on Exercise #28
+
+Find pairs of SGB word vectors that differ by +/-n.
+"""
+from get_words import get_words
+from euclidean_distance import euclidean_distance
+
+def diff_by_n(n):
+    k = 0
+    off_by_one = []
+    for i in range(len(words)):
+        for j in range(i,len(words)):
+            d = euclidean_distance(words[i],words[j])
+            if(abs(d)==n):
+                k += 1
+                off_by_one.append((words[i],words[j]))
+                print("{0:s}, {1:s}".format(words[i],words[j]))
+        if k>5:
+            break
+
+    #print("{0:d} words have a Euclidean distance of +/-{0:d}.".format(k,n))
+
+
+if __name__=="__main__":
+    words = get_words()
+    words = words[:1000]
+
+    for n in [1,2,3,4,5]:
+        print("-"*40)
+        print("Distance of {0:d}".format(n))
+        diff_by_n(n)
+