split

TP9/tri-fusion/merge_sort.py

@@ -61,7 +61,6 @@ def length(li: ApLst) -> int:
     else:
         return 1+length(li.tail())
     
-length(ApLst(3, ApLst(1, ApLst(4, ApLst()))))
 
 def native_to_list(li: list[T]) -> ApLst:
     """
@@ -143,7 +142,15 @@ def split(l: ApLst) -> tuple[ApLst, ApLst]:
     $$$ all(k in l for k in l3)
     True
     """
-    ...
+    if length(l)>=2:
+        l1=ApLst(l.head(),split((l.tail()).tail())[0])
+        l2=ApLst((l.tail()).head(),split((l.tail()).tail())[1])
+        return(l1,l2)
+    if l.is_empty():
+        return (ApLst(),ApLst())
+    if length(l)==1:
+        return (ApLst(l.head(),ApLst()),ApLst())
+    
 
 
 def merge(l1: ApLst, l2: ApLst,
@@ -158,7 +165,21 @@ def merge(l1: ApLst, l2: ApLst,
     $$$ list_to_native(merge(native_to_list([1, 3, 4, 9]), native_to_list([1, 2, 5])))
     [1, 1, 2, 3, 4, 5, 9]
     """
-    ...
+    res=[]
+    while not (l1.is_empty() or l2.is_empty()):
+        if comp(l1.head(),l2.head())<0:
+            res.append(l1.head())
+            l1=l1.tail()
+        else:
+            res.append(l2.head())
+            l2=l2.tail()
+    while not l1.is_empty():
+        res.append(l1.head())
+        l1=l1.tail()
+    while not l2.is_empty():
+        res.append(l2.head())
+        l2=l2.tail()
+    return native_to_list(res)
 
 
 def mergesort(l: ApLst, comp: Callable[[T, T], int]=compare) -> ApLst: