{"post":"

Program to find two’s complement of a binary number in C++

Problem – Binary Number as a string, we have to print its 2’s complement.

2’s complement of a binary number is another binary number obtained by adding 1 to one’s complement.

Example:

Input: 101010

One’s complement the number: 010110

Algorithm:

Take a binary number input as a string of length size.
Initialize an integer fail to 0.
Start a loop from i = 0 to i < size.\n
1. If binary[i] is equal to 1, set one[i] to 0.
2. Else, if binary[i] is equal to 0, set one[i] to 1.
3. Else, print an error message and set fail to 1. Break out of the loop.
\n
Place a null character at the end of the string one.
If fail is equal to 0, print the one's complement.
Start a loop from i = size - 1 to i >= 0.\n
1. If one[i] is equal to 1 and carry is equal to 1, set two[i] to 0.
2. Else, if one[i] is equal to 0 and carry is equal to 1, set two[i] to 1 and set carry to 0.
3. Else, set two[i] to one[i].
\n
Place a null character at the end of the string two.
If fail is equal to 0, print the two's complement.

Code:

// Program to find two's complement of a binary number\n#include <iostream>\n\n#define size 6\nusing namespace std;\n\nint main() {\n   char binary[size + 1], one[size + 1], two[size + 1];\n   int i, carry = 1, fail = 0;\n   cout << \"Input a \" << size << \" bit binary number: \";\n   cin >> binary;\n   for (i = 0; i < size; i++) {\n      if (binary[i] == '1') {\n         one[i] = '0';\n      } else if (binary[i] == '0') {\n         one[i] = '1';\n      } else {\n         cout << \"Error! Input the number of assigned bits.\" << endl;\n         fail = 1;\n         break;\n      }\n   }\n   one[size] = '\\0';\n\n   for (i = size - 1; i >= 0; i--) {\n      if (one[i] == '1' && carry == 1) {\n         two[i] = '0';\n      } else if (one[i] == '0' && carry == 1) {\n         two[i] = '1';\n         carry = 0;\n      } else {\n         two[i] = one[i];\n      }\n   }\n   two[size] = '\\0';\n   if (fail == 0) {\n      cout << \"The original binary = \" << binary << endl;\n      cout << \"After ones complement the value = \" << one << endl;\n      cout << \"After twos complement the value = \" << two << endl;\n   }\n}\n\n

Output

Input a 6 bit binary number: 101101\nThe original binary = 101101\nAfter ones complement the value = 010010\nAfter twos complement the value = 010011\n\n

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