restructure, slow security solution

2018-01-30 02:02:02 -05:00
parent c9be15672c
commit c925681921
18 changed files with 284 additions and 57 deletions
--- a/intset.py
+++ b/intset.py
@@ -0,0 +1,111 @@
+class IntSet:
+    def __init__(self, *bounds):
+        """Bounds must be tuples of the form (a, b),
+        where integers a <= x < b are included in the set.
+        """
+
+        if not bounds:
+            bounds = [0, 0]
+
+        self.bounds = list(bounds)
+
+    def simplify(self):
+        i = 0
+        while i < len(self.bounds) - 1:
+            if i % 2 == 0:
+                if self.bounds[i] >= self.bounds[i + 1]:
+                    del self.bounds[i:i + 2]
+                else:
+                    i += 1
+            else:
+                if self.bounds[i] >= self.bounds[i + 1]:
+                    if self.bounds[i] >= self.bounds[i + 2]:
+                        del self.bounds[i + 1:i + 3]
+                    else:
+                        del self.bounds[i:i + 2]
+                else:
+                    i += 1
+
+    def __or__(self, other):
+        bounds = None
+        j = k = 0
+
+        while j < len(self.bounds) - 1 or k < len(other.bounds) - 1:
+            if k >= len(other.bounds) - 1:
+                a, b = self.bounds[j:j + 2]
+                j += 2
+            elif j >= len(self.bounds) - 1:
+                a, b = other.bounds[k:k + 2]
+                k += 2
+            elif self.bounds[j] < other.bounds[k]:
+                a, b = self.bounds[j:j + 2]
+                j += 2
+            else:
+                a, b = other.bounds[k:k + 2]
+                k += 2
+
+            if a >= b:
+                continue
+
+            if not bounds:
+                bounds = [a, b]
+                continue
+
+            e = bounds[-1]
+
+            if e >= a:
+                if e >= b:
+                    continue
+                bounds[-1] = b
+            else:
+                bounds.append(a)
+                bounds.append(b)
+
+        if not bounds:
+            bounds = [0, 0]
+
+        new = IntSet()
+        new.bounds = bounds
+        return new
+
+    def __and__(self, other):
+        bounds = []
+
+        i = j = 0
+        while i < len(self.bounds) - 1 and j < len(other.bounds) - 1:
+            a, b = self.bounds[i:i + 2]
+            c, d = other.bounds[j:j + 2]
+            if b > c and a < d:
+                bounds.append(max(a, c))
+                bounds.append(min(b, d))
+            if b < d:
+                i += 2  # toss a b
+            else:
+                j += 2  # toss c d
+
+        new = IntSet()
+        new.bounds = bounds
+        new.simplify()
+        return new
+
+    def __eq__(self, other):
+        return self.bounds == other.bounds
+
+    def __iter__(self):
+        for a, b in self.pairs:
+            yield from range(a, b)
+
+    def __len__(self):
+        return sum(b - a if b > a else 0 for a, b in self.pairs)
+
+    def __lt__(self, other):
+        return len(self) < len(other)
+
+    @property
+    def pairs(self):
+        it = iter(self.bounds)
+        while True:
+            yield next(it), next(it)
+
+    def __repr__(self):
+        return 'U'.join('[{0},{1})'.format(a, b) for a, b in self.pairs)