Dangling exercises for midterm

midterm_prep/183-2.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+
+import sys
+import math
+
+def better_algo_X(A, k):
+    l = -1 * math.inf
+    r = math.inf
+    for i in range(0, len(A)):
+        c = 0
+        for j in range(i, len(A)):
+            print("i =", i, "j =", j, "c =", c)
+            if A[i] == A[j]:
+                c = c + 1
+                if c >= k:
+                    if r - l > j - i:
+                        l = i
+                        r = j
+                        print("l =", l, "r = ", r)
+                    break
+    return [l, r]
+
+A = []
+for line in sys.stdin:
+    line = line.strip()
+    if line == '' or line == '\n':
+        break
+    A.append(int(line))
+
+print(better_algo_X(A[1:], A[0]))

midterm_prep/184-1.py

@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+
+import sys
+import math
+
+def three_way_partition(A, begin, end):
+    i = 0
+    j = end - 2
+    p = end - 1
+    while i < j:
+        print(A[begin:i], A[i:j+1], A[j+1:p], A[p:end])
+        if A[i] == A[p]:
+            p = p - 1
+            A[i], A[p] = A[p], A[i]
+            if j == p:
+                j = j - 1
+        elif A[j] == A[p]:
+            p = p - 1
+            A[j], A[p] = A[p], A[j]
+            if j == p:
+                j = j - 1
+        elif A[i] < A[p]:
+            i = i + 1
+        elif A[j] > A[p]:
+            j = j - 1
+        else:
+            A[i], A[j] = A[j], A[i]
+
+    m = end - 1
+    while i < p:
+        print(A)
+        A[i], A[m] = A[m], A[i]
+        m = m - 1
+        i = i + 1
+
+    return [j, m + 1]
+
+if __name__ == "__main__":
+    A = []
+    for line in sys.stdin:
+        line = line.strip()
+        if line == '' or line == '\n':
+            break
+        A.append(int(line))
+
+    print(three_way_partition(A, 0, len(A)))
+    print(A)

midterm_prep/184-1.txt

@@ -0,0 +1,25 @@
+1
+2
+3
+4
+5
+5
+5
+4
+32
+21
+6
+8
+34
+98
+3426
+56
+3
+67
+2
+6
+2
+6
+23
+65
+