Merge pull request #84 from fromfall/patch-15

Петров 9

lab9/lab9.py

@@ -0,0 +1,97 @@
+import random
+from sys import stdin
+
+class Heap:
+    def __init__(self):
+        self.a = []
+    def _down(self, i):
+        while 2 * i + 1 < len(self.a):
+            left = 2 * i + 1
+            right = 2 * i + 2
+            j = left
+            if right < len(self.a) and self.a[right] < self.a[left]:
+                j = right
+            if self.a[i] <= self.a[j]:
+                break
+            self.a[i], self.a[j] = self.a[j], self.a[i]
+            i = j
+    def _up(self, i):
+        while i > 0 and self.a[i] < self.a[(i - 1) // 2]:
+            self.a[i], self.a[(i - 1) // 2] = self.a[(i - 1) // 2], self.a[i]
+            i = (i - 1) // 2
+    def min(self):
+        res = self.a[0]
+        if (len(self.a) > 1):
+            self.a[0] = self.a.pop()
+        else:
+            self.a.pop()
+        self._down(0)
+        return res
+    def insert(self, k):
+        self.a.append(k)
+        self._up(len(self.a) - 1)
+
+def part1(a, k):
+    h = Heap()
+    for i in a:
+        h.insert(i)
+        if (len(h.a) > k):
+            h.min()
+    return h.a
+
+
+def _partition5(a, l, r):
+    for i in range(l, r):
+        for j in range(i, r):
+            if a[j] > a[j + 1]:
+                a[j], a[j + 1] = a[j + 1], a[j]
+    return (r + l) // 2
+
+def _partition(a, l, r):
+    if (r - l <= 4):
+        return _partition5(a, l, r)
+    t = []
+    for i in range(5):
+        randr = random.randint(l, r - 4)
+        ta = a[randr:randr + 5]
+        t.append(ta[_partition5(ta, 0, 4)])
+    _partition5(t, 0, 4)
+    x = t[2]
+    i = l
+    j = r
+    while 1:
+        while a[i] < x:
+            i = i + 1
+        while a[j] > x:
+            j = j - 1
+        if i < j:
+            a[i], a[j] = a[j], a[i]
+            i += 1
+            j -= 1
+        else:
+            return j
+
+
+def part2(a, n):
+    if len(a) == 1:
+        return a[0]
+    left = 0
+    right = len(a) - 1
+    k = len(a) - n - 1
+    b = sorted(a)
+    while 1:
+        mid = _partition(a, left, right)
+        if mid == k:
+            return a[-n:]
+        elif k < mid:
+            right = mid
+        else:
+            left = mid + 1
+
+if __name__ == '__main__':
+    a = [int(i) for i in stdin.readline().split()]
+    n = int(input())
+    r1 = part1(a, n)
+    print (r1)
+    r2 = part2(a, n)
+    print(r2)

lab9/test9.py

@@ -0,0 +1,31 @@
+import lab9
+import unittest
+import random
+
+class TestKMax(unittest.TestCase):
+    def test_random(self):
+        a = random.sample(range(100), 50) + random.sample(range(100), 50)
+        r1 = lab9.part1(a, 40)
+        r2 = lab9.part2(a, 40)
+        r = sorted(a)[-40:]
+        self.assertEqual(r, sorted(r1))
+        self.assertEqual(r, sorted(r2))
+    def test_ones(self):
+        length = 100000
+        k = 10000
+        a = [1 for i in range(length)]
+        r1 = lab9.part1(a, k)
+        r2 = lab9.part2(a, k)
+        r = a[-k:]
+        self.assertEqual(r, r1)
+        self.assertEqual(r, r2)
+    def test_long_random(self):
+        a = random.sample(range(100000), 20000)
+        r1 = lab9.part1(a, 10000)
+        r2 = lab9.part2(a, 10000)
+        r = sorted(a)[-10000:]
+        self.assertEqual(r, sorted(r1))
+        self.assertEqual(r, sorted(r2))
+
+suite = unittest.TestLoader().loadTestsFromTestCase(TestKMax)
+unittest.TextTestRunner(verbosity=2).run(suite)