Convert a number into a corresponding excel column name
Given a positive number, convert the number to the corresponding Excel column name.
For example, the following image shows numbers corresponding to Excel columns:
The main trick in this problem lies in handling the boundary cases, such as the number 26 corresponds to column Z, and the number 27 corresponds to column AA. Similarly, the number 1014 corresponds to column ALZ, and the number 1015 corresponds to column AMA.
Following is the C++, Java, and Python program that handles all these cases beautifully:
C++
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 |
#include <iostream> #include <string> #include <cstdlib> #include <ctime> using namespace std; // Function to convert a given number to an Excel column string getColumnName(int n) { // initialize output string as empty string result = ""; while (n > 0) { // find the index of the next letter and concatenate the letter // to the solution // here index 0 corresponds to 'A', and 25 corresponds to 'Z' int index = (n - 1) % 26; result = char(index + 'A') + result; n = (n - 1) / 26; } return result; } int main() { // seed for random input srand(time(NULL)); // generate column names for 10 random numbers between 1–1000 for (int i = 1; i <= 10; i++) { int r = rand() % 1000 + 1; cout << r << " — " << getColumnName(r) << endl; } return 0; } |
Java
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 |
import java.util.Random; class Main { // Function to convert a given number to an Excel column public static String getColumnName(int n) { // initialize output string as empty StringBuilder result = new StringBuilder(); while (n > 0) { // find the index of the next letter and concatenate the letter // to the solution // here index 0 corresponds to 'A', and 25 corresponds to 'Z' int index = (n - 1) % 26; result.append((char)(index + 'A')); n = (n - 1) / 26; } return result.reverse().toString(); } public static void main(String[] args) { // generate column names for 10 random numbers between 1–1000 for (int i = 1; i <= 10; i++) { int r = new Random().nextInt(1000) + 1; System.out.println(r + " — " + getColumnName(r)); } } } |
Python
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 |
from random import randint # Function to convert a given number to an Excel column def getColumnName(n): # initialize output string as empty result = '' while n > 0: # find the index of the next letter and concatenate the letter # to the solution # here index 0 corresponds to 'A', and 25 corresponds to 'Z' index = (n - 1) % 26 result += chr(index + ord('A')) n = (n - 1) // 26 return result[::-1] if __name__ == '__main__': # generate column names for 10 random numbers between 1–1000 for i in range(1, 11): r = randint(1, 1000) print(r, '—', getColumnName(r)) |
585 — VM
873 — AGO
269 — JI
849 — AFQ
288 — KB
962 — AJZ
549 — UC
572 — UZ
485 — RQ
704 — AAB
Also See:
Thanks for reading.
To share your code in the comments, please use our online compiler that supports C, C++, Java, Python, JavaScript, C#, PHP, and many more popular programming languages.
Like us? Refer us to your friends and support our growth. Happy coding :)