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[Swift]LeetCode762. 二进制表示中质数个计算置位 | Prime Number of Set Bits in Binary Representation

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Given two integers L and R, find the count of numbers in the range [L, R] (inclusive) having a prime number of set bits in their binary representation.

(Recall that the number of set bits an integer has is the number of 1s present when written in binary. For example, 21 written in binary is 10101 which has 3 set bits. Also, 1 is not a prime.) 

Example 1:

Input: L = 6, R = 10
Output: 4
Explanation:
6 -> 110 (2 set bits, 2 is prime)
7 -> 111 (3 set bits, 3 is prime)
9 -> 1001 (2 set bits , 2 is prime)
10->1010 (2 set bits , 2 is prime) 

Example 2:

Input: L = 10, R = 15
Output: 5
Explanation:
10 -> 1010 (2 set bits, 2 is prime)
11 -> 1011 (3 set bits, 3 is prime)
12 -> 1100 (2 set bits, 2 is prime)
13 -> 1101 (3 set bits, 3 is prime)
14 -> 1110 (3 set bits, 3 is prime)
15 -> 1111 (4 set bits, 4 is not prime) 

Note:

  1. L, R will be integers L <= R in the range [1, 10^6].
  2. R - L will be at most 10000.

给定两个整数 L 和 R ，找到闭区间 [L, R] 范围内，计算置位位数为质数的整数个数。

（注意，计算置位代表二进制表示中1的个数。例如 21 的二进制表示 10101 有 3 个计算置位。还有，1 不是质数。）

示例 1:

输入: L = 6, R = 10
输出: 4
解释:
6 -> 110 (2 个计算置位，2 是质数)
7 -> 111 (3 个计算置位，3 是质数)
9 -> 1001 (2 个计算置位，2 是质数)
10-> 1010 (2 个计算置位，2 是质数)

示例 2:

输入: L = 10, R = 15
输出: 5
解释:
10 -> 1010 (2 个计算置位, 2 是质数)
11 -> 1011 (3 个计算置位, 3 是质数)
12 -> 1100 (2 个计算置位, 2 是质数)
13 -> 1101 (3 个计算置位, 3 是质数)
14 -> 1110 (3 个计算置位, 3 是质数)
15 -> 1111 (4 个计算置位, 4 不是质数)

注意:

  1. L, R 是 L <= R 且在 [1, 10^6] 中的整数。
  2. R - L 的最大值为 10000。
Runtime: 16 ms
Memory Usage: 18.6 MB
 1 class Solution {
 2     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3         
 4         var count = 0
 5         for i in L...R {
 6             let nonzeroBitCount = i.nonzeroBitCount
 7             
 8             if isPrime(nonzeroBitCount) {
 9                 count += 1
10             }
11         }
12         
13         return count
14     }
15     
16     private func isPrime(_ num: Int) -> Bool {
17         guard num > 1 else {
18             return false
19         }
20         
21         guard num != 2 else {
22             return true
23         }
24         
25         guard num & 1 == 1 else {
26             return false
27         }
28         
29         var i = 3
30         
31         while i * i <= num, num % i != 0 {
32             i += 2
33         }
34         
35         return i * i > num
36     }
37 }

36ms

 1 class Solution {
 2     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3         
 4         var count = 0
 5         
 6         for i in L...R {
 7             
 8             let bitCode = i.nonzeroBitCount
 9             if isSmallPrime(bitCode) {
10                 count += 1
11             }
12         }
13         
14         return count
15     }
16     
17     func isSmallPrime(_ i: Int) -> Bool {
18         
19         switch i {
20         case 2,3,5,7,11,13,17,19:
21             return true
22         default:
23             return false
24         }
25     }
26 }

52ms

 1 class Solution {
 2     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3         var  count = 0
 4         for num in L...R {
 5             
 6             let bits = getSetBits(num)
 7             
 8             if isPrime(bits) {
 9                 count += 1
10             }
11             
12         }
13         
14         return count
15     }
16     
17     
18     func getSetBits(_ num : Int) -> Int {
19         var count = 0
20         var v = num
21         
22         while v >= 1 {
23             v &= v - 1 
24             count += 1
25         }
26         return count
27     }
28     
29     func isPrime(_ n : Int ) -> Bool {
30         if n <= 1 { return false }
31         if n <= 3 { return true }
32         
33         if n % 2 == 0 || n % 3 == 0 { return false }
34         
35         var i = 5
36         while Int(pow(Double(i), Double(i))) <= n {
37             if  n % i == 0 || n%(i+2) == 0 {
38                 return false
39             }
40 
41             i = i + 6
42         }
43         
44         return true
45     }
46 }

96ms

 1 class Solution {
 2     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3         var res = 0
 4         let primes = Set([2, 3, 5, 7, 11, 13, 17, 19])
 5 
 6         for i in L...R {
 7             res += primes.contains(bitCount(i)) ? 1 : 0
 8         }
 9 
10         return res
11     }
12 
13     private func bitCount(_ n: Int) -> Int {
14         var count = 0
15         var n = n
16 
17         while n > 0 {
18             n &= n - 1
19             count += 1
20         }
21 
22         return count
23     }
24 }

372ms

 1 class Solution {
 2     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3         
 4         var count = 0
 5         for i in L...R {
 6             let nonzeroBitCount = i.nonzeroBitCount
 7             
 8             var isPrime = true
 9             if nonzeroBitCount == 1 {
10                 isPrime = false
11             } else {
12                 for factor in stride(from: 2, to: nonzeroBitCount, by: 1) {
13                     if nonzeroBitCount % factor == 0 {
14                         isPrime = false
15                         break
16                     }
17                 }
18             }
19             
20             count += isPrime ? 1 : 0
21         }
22         
23         return count
24     }
25 }

460ms

 1 class Solution {
 2   func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3     let primeMap = [0,0,1,1,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,1,0,0,0,1,0,0,0,0,0,1,0,1,0]
 4     
 5     var count = 0
 6     
 7     for num in L...R {
 8       var n = num
 9       var oneCount = 0
10       while n > 0 {
11         if n & 1 == 1 {
12           oneCount += 1
13         }
14         n >>= 1
15       }
16       count += primeMap[oneCount]
17     }
18     
19     return count
20   }
21 }

620ms

 1 class Solution {
 2     // 输入区间为 1...10^6, 既最大为20位, 直接取20以内质数
 3     let c = [2, 3, 5, 7, 11, 13, 17, 19]
 4     
 5     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 6         return (L...R).reduce(0) {
 7             $0 + (c.contains($1.nonzeroBitCount) ? 1 : 0)
 8         }
 9     }
10 }

944ms

 1 class Solution {
 2     
 3     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 4         var numPrime = 0
 5         let primes = [ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31]
 6         for i in L...R {
 7             var numOnes = 0
 8             for j in 0..<32 {
 9                 if (i >> j) & 1 != 0 {
10                     numOnes += 1
11                 }
12             }
13             if primes.contains(numOnes) {
14                 numPrime += 1
15             }
16         }
17         return numPrime
18     }
19     
20 }

1460ms

 1 class Solution {
 2     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3     var result: Int = 0
 4     for i in L...R {
 5         let binaryString = String(i, radix: 2)
 6         if isPrime(numberOfSetBits(binaryString)) { result += 1 }
 7     }
 8 
 9     return result
10 }
11 
12 func isPrime(_ num: Int) -> Bool {
13     guard num >= 2 else { return false }
14 
15     for i in 2..<num {
16         if num % i == 0 { return false }
17     }
18     
19     return true
20 }
21 
22 func numberOfSetBits(_ text: String) -> Int {
23     guard text != "" else { return 0 }
24     var result: Int = 0
25     
26     text.characters.forEach { (char) in
27         if char == "1" { result += 1 }
28     }
29     
30     return result
31   }
32 }

1840ms

 1 class Solution {
 2     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3         var statistics: [Int] = Array(repeating: 0, count: R-L+1)
 4         for (i, v) in (L...R).enumerated() {
 5             // 二进制操作数
 6             var vt = v
 7             // 二进制置位累加值
 8             var va = 0
 9             while vt > 0 {
10                 if (vt >> 1) * 2 != vt {
11                     va += 1
12                 }
13                 vt = vt >> 1
14             }
15             statistics[i] = va
16         }
17         return filterPrimeNumber(for: statistics)
18     }
19     // 输入区间为 1...10^6, 既最大为20位, 直接取20以内质数
20     func filterPrimeNumber(for array: [Int]) -> Int {
21         let c = [2, 3, 5, 7, 11, 13, 17, 19]
22         var accumulator = 0
23         array.forEach({
24             if c.contains($0) { accumulator += 1 }
25         })
26         return accumulator
27     }
28 }

1948ms

 1 class Solution {
 2     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3         var count = 0 
 4         var out: [Int] = []
 5         for i in L...R {
 6             let bin = String(i, radix: 2)
 7             var numberOfOnes = 0 
 8             for char in bin {
 9                 if char == "1" {
10                     numberOfOnes += 1
11                 }
12             }
13             if isPrime(number: numberOfOnes) {
14                 out.append(i)
15             }
16         }
17         return out.count 
18     }
19     
20     func isPrime(number: Int) -> Bool {
21      return number > 1 && !(2..<number).contains { number % $0 == 0 }
22     }
23 }

2648ms

 1 class Solution {
 2     func countPrimeSetBits(_ L: Int, _ R: Int) -> Int {
 3         var result = 0
 4         for v in L...R {
 5             if isPrime(Array(String(v, radix: 2)).filter {$0 == "1"}.count) {
 6                 result += 1
 7             }
 8         }
 9         
10         return result
11     }
12     
13     func isPrime(_ number: Int) -> Bool {
14         return number > 1 && !(2..<Int(sqrt(Double(number)))+1).contains { number % $0 == 0 }
15     }
16 }

 

posted @ 2019-03-14 20:03  为敢技术  阅读(397)  评论(0)  编辑  收藏  举报