Finish week 1 problem set and merge sort in Rust

py/week_1_merge_sort.py

@@ -0,0 +1,37 @@
+
+def merge(a, b):
+    """Merges two sorted lists"""
+    i, j = 0, 0
+    r = []
+    while i < len(a) and j < len(b):
+        if a[i] < b[j]:
+            r.append(a[i])
+            i += 1
+        else:
+            r.append(b[j])
+            j += 1
+
+    while i < len(a):
+        r.append(a[i])
+        i += 1
+
+    while j < len(b):
+        r.append(b[j])
+        j += 1
+    return r
+
+
+def merge_sort(v):
+    length = len(v)
+    if length <= 1:
+        return v
+
+    half_length = length // 2
+
+    a = merge_sort(v[:half_length])
+    b = merge_sort(v[half_length:])
+    return merge(a, b)
+
+
+if __name__ == "__main__":
+    print(merge_sort([42, 12, 3, 1, 5]))