Find Excel column name from a given column number

MS Excel columns has a pattern like A, B, C, … ,Z, AA, AB, AC,…. ,AZ, BA, BB, … ZZ, AAA, AAB ….. etc. In other words, column 1 is named as “A”, column 2 as “B”, column 27 as “AA”.

Given a column number, find its corresponding Excel column name. Following are more examples.

Input          Output
26             Z
51             AY
52             AZ
80             CB
676            YZ
702            ZZ
705            AAC

Thanks to Mrigank Dembla for suggesting the below solution in a comment.

Suppose we have a number n, let’s say 28. so corresponding to it we need to print the column name. We need to take remainder with 26.

If remainder with 26 comes out to be 0 (meaning 26, 52 and so on) then we put ‘Z’ in the output string and new n becomes n/26 -1 because here we are considering 26 to be ‘Z’ while in actual it’s 25th with respect to ‘A’.

Similarly if the remainder comes out to be non zero. (like 1, 2, 3 and so on) then we need to just insert the char accordingly in the string and do n = n/26.

Finally we reverse the string and print.

Example:
n = 700

Remainder (n%26) is 24. So we put ‘X’ in output string and n becomes n/26 which is 26.

Remainder (26%26) is 0. So we put ‘Z’ in output string and n becomes n/26 -1 which is 0.

Following is C++ implementation of above approach.

C++

 // C++ program to find Excel  // column name from a given  // column number #include #define MAX 50 using namespace std;    // Function to print Excel column name for a given column number void printString(int n) {     char str[MAX]; // To store result (Excel column name)     int i = 0; // To store current index in str which is result        while (n>0)     {         // Find remainder         int rem = n%26;            // If remainder is 0, then a 'Z' must be there in output         if (rem==0)         {             str[i++] = 'Z';             n = (n/26)-1;         }         else // If remainder is non-zero         {             str[i++] = (rem-1) + 'A';             n = n/26;         }     }     str[i] = '';        // Reverse the string and print result     reverse(str, str + strlen(str));     cout << str << endl;        return; }    // Driver program to test above function int main() {     printString(26);     printString(51);     printString(52);     printString(80);     printString(676);     printString(702);     printString(705);     return 0; }

Java

 // Java program to find Excel  // column name from a given  // column number    public class ExcelColumnTitle {     // Function to print Excel column     // name for a given column number     private static void printString(int columnNumber)     {         // To store result (Excel column name)         StringBuilder columnName = new StringBuilder();            while (columnNumber > 0)         {             // Find remainder             int rem = columnNumber % 26;                // If remainder is 0, then a              // 'Z' must be there in output             if (rem == 0)             {                 columnName.append("Z");                 columnNumber = (columnNumber / 26) - 1;             }             else // If remainder is non-zero             {                 columnName.append((char)((rem - 1) + 'A'));                 columnNumber = columnNumber / 26;             }         }            // Reverse the string and print result         System.out.println(columnName.reverse());     }        // Driver program to test above function     public static void main(String[] args)     {         printString(26);         printString(51);         printString(52);         printString(80);         printString(676);         printString(702);         printString(705);     } }    // This code is contributed by Harikrishnan Rajan

Python

 # Python program to find Excel column name from a  # given column number    MAX = 50    # Function to print Excel column name  # for a given column number def printString(n):        # To store result (Excel column name)     string = [""] * MAX        # To store current index in str which is result     i = 0        while n > 0:         # Find remainder         rem = n % 26            # if remainder is 0, then a          # 'Z' must be there in output         if rem == 0:             string[i] = 'Z'             i += 1             n = (n / 26) - 1         else:             string[i] = chr((rem - 1) + ord('A'))             i += 1             n = n / 26     string[i] = ''        # Reverse the string and print result     string = string[::-1]     print "".join(string)    # Driver program to test the above Function printString(26) printString(51) printString(52) printString(80) printString(676) printString(702) printString(705)    # This code is contributed by BHAVYA JAIN

Output

Z
AY
AZ
CB
YZ
ZZ
AAC

Related Article :
Find Excel column number from column title