School Commit Init

Anul 1/Semestrul 1/Fundamentals of Programming/FP/src/lecture/examples/ex17_backtracking.py

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+"""
+Created on Jan 10, 2017
+
+@author: Arthur
+"""
+
+import time
+from texttable import *
+
+
+def generate_test(array, dim):
+    if len(array) == dim:
+        # print (array)
+        pass
+    if len(array) > dim:
+        return
+    array.append(0)
+    for i in range(0, dim):
+        array[-1] = i
+        generate_test(array[:], dim)
+
+
+def backtracking_iter(dim: int):
+    array = [-1]  # candidate solution
+    while len(array) > 0:
+        chosen = False
+        while not chosen and array[-1] < dim - 1:
+            array[-1] = array[-1] + 1  # increase the last component
+            chosen = len(set(array)) == len(array)
+        if chosen:
+            if len(array) == dim:
+                print(array)
+            array.append(-1)  # expand candidate solution
+        else:
+            array = array[:-1]  # go back one component
+
+
+def backtracking_rec(array, dim):
+    if len(array) == dim:
+        print(array)
+    if len(array) > dim:
+        return
+    array.append(0)
+    for i in range(0, dim):
+        array[-1] = i
+        if len(set(array)) == len(array):
+            backtracking_rec(array, dim)
+            array.pop()
+
+
+'''
+And here we build our experiment
+'''
+functions = [generate_test, backtracking_rec]
+data_sizes = [3, 4, 5, 6, 7]
+
+t = Texttable()
+t.add_row(['Functions'] + data_sizes)
+for function in functions:
+    row = [function.__name__]
+    for size in data_sizes:
+        t1 = time.perf_counter()
+        function([], size)
+        t2 = time.perf_counter()
+        row = row + [t2 - t1]
+    t.add_row(row)
+print(t.draw())