one away coding question

Sure! Here is an example of a solution to a "one away" coding question in C++, along with explanations for each step:

#include <iostream>
#include <string>
using namespace std;

bool isOneAway(string str1, string str2) {
    int len1 = str1.length();
    int len2 = str2.length();

    // If the difference in lengths is more than 1, they can't be one away
    if (abs(len1 - len2) > 1) {
        return false;
    }

    int count = 0;
    int i = 0, j = 0;

    while (i < len1 && j < len2) {
        // If characters are different
        if (str1[i] != str2[j]) {
            // If this is the second mismatch, they can't be one away
            if (count == 1) {
                return false;
            }

            // If lengths are different, move the pointer of the longer string
            if (len1 > len2) {
                i++;
            } else if (len1 < len2) {
                j++;
            } else { // If lengths are the same, move both pointers
                i++;
                j++;
            }

            count++; // Increment the mismatch count
        } else { // If characters are the same, move both pointers
            i++;
            j++;
        }
    }

    // If there are remaining characters in either string, increment the mismatch count
    if (i < len1 || j < len2) {
        count++;
    }

    // If the mismatch count is at most 1, they are one away
    return count <= 1;
}

int main() {
    string str1, str2;
    cout << "Enter the first string: ";
    cin >> str1;
    cout << "Enter the second string: ";
    cin >> str2;

    if (isOneAway(str1, str2)) {
        cout << "The strings are one away." << endl;
    } else {
        cout << "The strings are not one away." << endl;
    }

    return 0;
}

Explanation:

We start by including the necessary headers, iostream for input/output operations and string for string manipulation.
We define a function isOneAway that takes two strings, str1 and str2, as input and returns a boolean value indicating whether they are "one away" from each other.
We get the lengths of both strings using the length() function and store them in variables len1 and len2.
We check if the difference in lengths is more than 1. If it is, then the strings can't be one away, so we return false.
We initialize a variable count to keep track of the number of mismatches and two variables i and j to iterate through the strings.
We start a while loop that runs until we reach the end of either string.
Inside the loop, we check if the characters at the current positions i and j are different. If they are, we handle the mismatch.
If this is the second mismatch (i.e., count is already equal to 1), then the strings can't be one away, so we return false.
If the lengths of the strings are different, we move the pointer of the longer string (i or j) to the next character. This accounts for the case where one string is longer than the other and we need to check if deleting or inserting a character would make them one away.
If the lengths of the strings are the same, we move both pointers to the next character. This accounts for the case where we need to check if replacing a character would make the strings one away.
After handling the mismatch, we increment the count variable.
If we reach the end of either string, there may be remaining characters in the other string. In this case, we increment the count variable to account for the remaining characters.
Finally, we check if the count is at most 1. If it is, then the strings are one away, so we return true. Otherwise, we return false.
In the main function, we prompt the user to enter two strings and store them in variables str1 and str2.
We call the isOneAway function with str1 and str2 as arguments and check the return value.
Depending on the return value, we output the appropriate message indicating whether the strings are one away or not.
The program ends by returning 0 to indicate successful execution.

I hope this explanation helps! Let me know if you have any further questions.