[Swift]LeetCode476. 數字的補數 | Number Complement
阿新 • • 發佈:2019-02-02
max sig != 輸出 sub ade += signed NPU
Runtime: 8 ms Memory Usage: 3.8 MB
Runtime: 8 ms Memory Usage: 3.8 MB
Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.
Note:
- The given integer is guaranteed to fit within the range of a 32-bit signed integer.
- You could assume no leading zero bit in the integer’s binary representation.
Example 1:
Input: 5 Output: 2 Explanation: The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2.
Example 2:
Input: 1 Output: 0 Explanation: The binary representation of 1 is 1 (no leading zero bits), and its complement is 0. So you need to output 0.
給定一個正整數,輸出它的補數。補數是對該數的二進制表示取反。
註意:
- 給定的整數保證在32位帶符號整數的範圍內。
- 你可以假定二進制數不包含前導零位。
示例 1:
輸入: 5 輸出: 2 解釋: 5的二進制表示為101(沒有前導零位),其補數為010。所以你需要輸出2。
示例 2:
輸入: 1 輸出: 0 解釋: 1的二進制表示為1(沒有前導零位),其補數為0。所以你需要輸出0。
Runtime: 8 ms Memory Usage: 3.8 MB
1 class Solution { 2 func findComplement(_ num: Int) -> Int {3 return (1 - num % 2) + 2 * (num <= 1 ? 0 : findComplement(num / 2)) 4 } 5 }
Runtime: 8 ms Memory Usage: 3.8 MB
1 class Solution { 2 func findComplement(_ num: Int) -> Int { 3 var mask:Int = Int.max 4 while ((mask & num) != 0) 5 { 6 mask <<= 1 7 } 8 return ~mask & ~num 9 } 10 }
8ms
1 class Solution { 2 func findComplement(_ num: Int) -> Int { 3 var numberOfBitsNeeded = 0 4 var number = num 5 while number > 0 { 6 number /= 2 7 numberOfBitsNeeded += 1 8 } 9 10 11 let allOnes = (2 << (numberOfBitsNeeded - 1)) - 1 12 13 14 return (num ^ allOnes) 15 } 16 }
3842 kb
1 class Solution { 2 func findComplement(_ num: Int) -> Int { 3 let numberOfBits = (String(num,radix:2)).count 4 return ((1 << numberOfBits) - 1) ^ num 5 } 6 }
3858 kb
1 class Solution { 2 func findComplement(_ num: Int) -> Int { 3 4 let bitCount = num.bitWidth - num.leadingZeroBitCount 5 6 var mask = 1 7 8 for _ in 0..<bitCount - 1 { 9 mask = mask << 1 + 1 10 } 11 12 return num ^ mask 13 } 14 }
16ms
1 class Solution { 2 func findComplement(_ b: Int) -> Int { 3 var count = 0 4 var sum = 0 5 while sum <= b { 6 count += 1 7 sum = 1 << count 8 } 9 10 let rtn = sum - 1 - b 11 return rtn 12 } 13 }
28ms
1 class Solution { 2 func findComplement(_ num: Int) -> Int { 3 var num = num 4 var res = 0 5 var offset = 0 6 7 while num > 0 { 8 res = res + ((num & 1) ^ 1) << offset 9 num = num >> 1 10 offset += 1 11 } 12 13 return res 14 } 15 }
[Swift]LeetCode476. 數字的補數 | Number Complement