c++ stoi binary negative number string to decimal

The std::stoi function in C++ is used to convert a string representing an integer to its corresponding decimal value. It can handle both positive and negative integers in decimal form.

To convert a binary string representation of a negative number to decimal using std::stoi, you can follow these steps:

1. Convert the binary string to a negative decimal string: If the binary string represents a negative number, it needs to be converted to a negative decimal string. This can be done by adding a negative sign ("-") at the beginning of the string.

2. Call std::stoi to convert the string to decimal: Once you have the negative decimal string, you can pass it to the std::stoi function. This function takes a string as input and returns the corresponding decimal value as an int.

Here is an example code snippet that demonstrates the conversion:

#include <iostream>
#include <string>

int main() {
    std::string binaryStr = "-1010101"; // Example binary string

    // Step 1: Convert the binary string to a negative decimal string
    std::string negativeDecimalStr = "-" + binaryStr.substr(1);

    // Step 2: Call std::stoi to convert the string to decimal
    int decimalValue = std::stoi(negativeDecimalStr);

    std::cout << "Decimal value: " << decimalValue << std::endl;

    return 0;
}

In this example, the binary string "-1010101" is converted to the negative decimal value -85 using std::stoi.

Please note that std::stoi expects a valid decimal string input. If the binary string is not a valid decimal representation, an exception of type std::invalid_argument or std::out_of_range may be thrown. It is important to handle these exceptions appropriately in your code.