.

bac1/q1/17nov/sort.py

@@ -0,0 +1,107 @@
+"""
+Voir commentaires concernant ce module dans l'enonce de la serie de TP.
+"""
+
+import random
+import umons_cpu
+
+def python_sort(t):
+    t.sort()
+
+def insertion_sort(t):
+    n = len(t)
+    for i in range(1,n):
+        clef = t[i]
+        j = i - 1
+        while j >= 0 and t[j] > clef:
+            t[j+1] = t[j]
+            j = j - 1
+        t[j+1] = clef
+
+def selection_sort(t):
+    n = len(t)
+    for i in range(n-1):
+        small = i
+        for j in range(i+1,n):
+            if t[j] < t[small]:
+                small = j
+        (t[i], t[small]) = (t[small], t[i])
+
+# permet d'avoir une interface in place, similaire aux autres tris
+def merge_sort(t):
+    t[:] = merge_sort_functionnal(t)
+
+def merge_sort_functionnal(t):
+    n = len(t)
+    if n > 1:
+        (t1, t2) = split(t)
+        t1 = merge_sort_functionnal(t1)
+        t2 = merge_sort_functionnal(t2)
+        return merge(t1, t2)
+    else:
+        return t
+
+def split(t):
+    """ precondition: len(t) >= 2 """
+    mid = len(t) // 2
+    t1 = t[:mid]
+    t2 = t[mid:]
+    return (t1, t2)
+
+def merge(t1, t2):
+    if len(t1) == 0:
+        return t2
+    elif len(t2) == 0:
+        return t1
+    elif t1[0] < t2[0]:
+        return [t1[0]] + merge(t1[1:], t2)
+    else:
+        return [t2[0]] + merge(t1, t2[1:])
+
+def dicho_search(t, x):
+    start = 0
+    end = len(t) - 1
+    mid = start + (end - start) // 2
+    while (end - start > 0) and x != t[mid]:
+        if x < t[mid]:
+            end = mid - 1
+        else:
+            start = mid + 1
+        mid = start + (end - start) // 2
+    if len(t) > 0 and x == t[mid]:
+        return mid
+    else:
+        return None
+
+def test(n):
+    t1 = list(range(n))
+    t2 = list(range(n,0,-1))
+    t3 = []
+    for i in range(n):
+        t3.append(random.randint(0,n))
+    print('%7d %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f' % (
+        n,
+        umons_cpu.cpu_time(selection_sort, t1),
+        umons_cpu.cpu_time(insertion_sort, t1),
+        umons_cpu.cpu_time(merge_sort, t1),
+        umons_cpu.cpu_time(selection_sort, t2),
+        umons_cpu.cpu_time(insertion_sort, t2),
+        umons_cpu.cpu_time(merge_sort, t2),
+        umons_cpu.cpu_time(selection_sort, t3),
+        umons_cpu.cpu_time(insertion_sort, t3),
+        umons_cpu.cpu_time(merge_sort, t3)))
+
+if __name__ == '__main__':
+    print('Temps affiches en msec')
+    print('      n '
+          't1: sel '
+          '    ins '
+          '    mer '
+          't2: sel '
+          '    ins '
+          '    mer '
+          't3: sel '
+          '    ins '
+          '    mer')
+    for i in range(100, 901, 100):
+        test(i)