-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathdesign-bitset.html
49 lines (42 loc) · 3.49 KB
/
design-bitset.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
<p>A <strong>Bitset</strong> is a data structure that compactly stores bits.</p>
<p>Implement the <code>Bitset</code> class:</p>
<ul>
<li><code>Bitset(int size)</code> Initializes the Bitset with <code>size</code> bits, all of which are <code>0</code>.</li>
<li><code>void fix(int idx)</code> Updates the value of the bit at the index <code>idx</code> to <code>1</code>. If the value was already <code>1</code>, no change occurs.</li>
<li><code>void unfix(int idx)</code> Updates the value of the bit at the index <code>idx</code> to <code>0</code>. If the value was already <code>0</code>, no change occurs.</li>
<li><code>void flip()</code> Flips the values of each bit in the Bitset. In other words, all bits with value <code>0</code> will now have value <code>1</code> and vice versa.</li>
<li><code>boolean all()</code> Checks if the value of <strong>each</strong> bit in the Bitset is <code>1</code>. Returns <code>true</code> if it satisfies the condition, <code>false</code> otherwise.</li>
<li><code>boolean one()</code> Checks if there is <strong>at least one</strong> bit in the Bitset with value <code>1</code>. Returns <code>true</code> if it satisfies the condition, <code>false</code> otherwise.</li>
<li><code>int count()</code> Returns the <strong>total number</strong> of bits in the Bitset which have value <code>1</code>.</li>
<li><code>String toString()</code> Returns the current composition of the Bitset. Note that in the resultant string, the character at the <code>i<sup>th</sup></code> index should coincide with the value at the <code>i<sup>th</sup></code> bit of the Bitset.</li>
</ul>
<p> </p>
<p><strong>Example 1:</strong></p>
<pre>
<strong>Input</strong>
["Bitset", "fix", "fix", "flip", "all", "unfix", "flip", "one", "unfix", "count", "toString"]
[[5], [3], [1], [], [], [0], [], [], [0], [], []]
<strong>Output</strong>
[null, null, null, null, false, null, null, true, null, 2, "01010"]
<strong>Explanation</strong>
Bitset bs = new Bitset(5); // bitset = "00000".
bs.fix(3); // the value at idx = 3 is updated to 1, so bitset = "00010".
bs.fix(1); // the value at idx = 1 is updated to 1, so bitset = "01010".
bs.flip(); // the value of each bit is flipped, so bitset = "10101".
bs.all(); // return False, as not all values of the bitset are 1.
bs.unfix(0); // the value at idx = 0 is updated to 0, so bitset = "00101".
bs.flip(); // the value of each bit is flipped, so bitset = "11010".
bs.one(); // return True, as there is at least 1 index with value 1.
bs.unfix(0); // the value at idx = 0 is updated to 0, so bitset = "01010".
bs.count(); // return 2, as there are 2 bits with value 1.
bs.toString(); // return "01010", which is the composition of bitset.
</pre>
<p> </p>
<p><strong>Constraints:</strong></p>
<ul>
<li><code>1 <= size <= 10<sup>5</sup></code></li>
<li><code>0 <= idx <= size - 1</code></li>
<li>At most <code>10<sup>5</sup></code> calls will be made <strong>in total</strong> to <code>fix</code>, <code>unfix</code>, <code>flip</code>, <code>all</code>, <code>one</code>, <code>count</code>, and <code>toString</code>.</li>
<li>At least one call will be made to <code>all</code>, <code>one</code>, <code>count</code>, or <code>toString</code>.</li>
<li>At most <code>5</code> calls will be made to <code>toString</code>.</li>
</ul>