给定二进制数作为字符串，打印其1和2的补码。
二进制数的1的补码是通过切换二进制数中的所有位(即，将0位转换为1和将1位转换为0)而获得的另一个二进制数。
例子：
1's complement of "0111" is "1000"
1's complement of "1100" is "0011" 二进制数的2的补码为1，再加上二进制数的1的补码。
例子：
2's complement of "0111" is "1001"
2's complement of "1100" is "0100" 寻找二的补码的另一个技巧：
第1步：从最低有效位开始，向左移动，直到找到1。直到找到1，这些位保持不变
第2步：找到1后，按原样设置1
步骤3：将剩下的所有位翻转为1。
插图
假设我们需要找到100100的2s补码
第1步：遍历并让位保持不变，直到找到1。此处x尚不为人所知。答案= xxxx00 –
步骤2 ：您发现1，保持不变。答案= xxx100
步骤3：将所有位翻转为1。答案= 011100。
因此，100100的2补码为011100。
为了补全，我们只需要翻转所有位。
对于2的补码，我们首先找到一个人的补码。我们从LSB(最低有效位)开始遍历一个补数，并查找0。我们翻转所有1(更改为0)，直到找到0。最后，翻转找到的0。例如，2的补数为“ 01000” ”是“ 11000”(请注意，我们首先找到01000的补码为10111)。如果全为1(在一个补码中)，则在字符串添加一个额外的1。例如，“ 000”的2的补码是“ 1000”(“ 000”的1的补码是“ 111”)。
下面是实现。
C++
// C++ program to print 1's and 2's complement of
// a binary number
#include
using namespace std;
// Returns '0' for '1' and '1' for '0'
char flip(char c) {return (c == '0')? '1': '0';}
// Print 1's and 2's complement of binary number
// represented by "bin"
void printOneAndTwosComplement(string bin)
{
int n = bin.length();
int i;
string ones, twos;
ones = twos = "";
// for ones complement flip every bit
for (i = 0; i < n; i++)
ones += flip(bin[i]);
// for two's complement go from right to left in
// ones complement and if we get 1 make, we make
// them 0 and keep going left when we get first
// 0, make that 1 and go out of loop
twos = ones;
for (i = n - 1; i >= 0; i--)
{
if (ones[i] == '1')
twos[i] = '0';
else
{
twos[i] = '1';
break;
}
}
// If No break : all are 1 as in 111 or 11111;
// in such case, add extra 1 at beginning
if (i == -1)
twos = '1' + twos;
cout << "1's complement: " << ones << endl;
cout << "2's complement: " << twos << endl;
}
// Driver program
int main()
{
string bin = "1100";
printOneAndTwosComplement(bin);
return 0;
} Java
// Java program to print 1's and 2's complement of
// a binary number
class GFG
{
// Returns '0' for '1' and '1' for '0'
static char flip(char c)
{
return (c == '0') ? '1' : '0';
}
// Print 1's and 2's complement of binary number
// represented by "bin"
static void printOneAndTwosComplement(String bin)
{
int n = bin.length();
int i;
String ones = "", twos = "";
ones = twos = "";
// for ones complement flip every bit
for (i = 0; i < n; i++)
{
ones += flip(bin.charAt(i));
}
// for two's complement go from right to left in
// ones complement and if we get 1 make, we make
// them 0 and keep going left when we get first
// 0, make that 1 and go out of loop
twos = ones;
for (i = n - 1; i >= 0; i--)
{
if (ones.charAt(i) == '1')
{
twos = twos.substring(0, i) + '0' + twos.substring(i + 1);
}
else
{
twos = twos.substring(0, i) + '1' + twos.substring(i + 1);
break;
}
}
// If No break : all are 1 as in 111 or 11111;
// in such case, add extra 1 at beginning
if (i == -1)
{
twos = '1' + twos;
}
System.out.println("1's complement: " + ones);;
System.out.println("2's complement: " + twos);
}
// Driver code
public static void main(String[] args)
{
String bin = "1100";
printOneAndTwosComplement(bin);
}
}
// This code contributed by Rajput-JiPython3
# Python3 program to print 1's and 2's
# complement of a binary number
# Returns '0' for '1' and '1' for '0'
def flip(c):
return '1' if (c == '0') else '0'
# Print 1's and 2's complement of
# binary number represented by "bin"
def printOneAndTwosComplement(bin):
n = len(bin)
ones = ""
twos = ""
# for ones complement flip every bit
for i in range(n):
ones += flip(bin[i])
# for two's complement go from right
# to left in ones complement and if
# we get 1 make, we make them 0 and
# keep going left when we get first
# 0, make that 1 and go out of loop
ones = list(ones.strip(""))
twos = list(ones)
for i in range(n - 1, -1, -1):
if (ones[i] == '1'):
twos[i] = '0'
else:
twos[i] = '1'
break
i -= 1
# If No break : all are 1 as in 111 or 11111
# in such case, add extra 1 at beginning
if (i == -1):
twos.insert(0, '1')
print("1's complement: ", *ones, sep = "")
print("2's complement: ", *twos, sep = "")
# Driver Code
if __name__ == '__main__':
bin = "1100"
printOneAndTwosComplement(bin.strip(""))
# This code is contributed
# by SHUBHAMSINGH10C#
// C# program to print 1's and 2's complement of
// a binary number
using System;
class GFG
{
// Returns '0' for '1' and '1' for '0'
static char flip(char c)
{
return (c == '0') ? '1' : '0';
}
// Print 1's and 2's complement of binary number
// represented by "bin"
static void printOneAndTwosComplement(String bin)
{
int n = bin.Length;
int i;
String ones = "", twos = "";
ones = twos = "";
// for ones complement flip every bit
for (i = 0; i < n; i++)
{
ones += flip(bin[i]);
}
// for two's complement go from right to left in
// ones complement and if we get 1 make, we make
// them 0 and keep going left when we get first
// 0, make that 1 and go out of loop
twos = ones;
for (i = n - 1; i >= 0; i--)
{
if (ones[i] == '1')
{
twos = twos.Substring(0, i) + '0' +
twos.Substring(i + 1,twos.Length-(i+1));
}
else
{
twos = twos.Substring(0, i) + '1' +
twos.Substring(i + 1,twos.Length-(i+1));
break;
}
}
// If No break : all are 1 as in 111 or 11111;
// in such case, add extra 1 at beginning
if (i == -1)
{
twos = '1' + twos;
}
Console.WriteLine("1's complement: " + ones);;
Console.WriteLine("2's complement: " + twos);
}
// Driver code
public static void Main(String[] args)
{
String bin = "1100";
printOneAndTwosComplement(bin);
}
}
// This code has been contributed by 29AjayKumar输出：
1's complement: 0011
2's complement: 0100