Excel Column Number
You have been given a column title as appears in an Excel sheet, return its corresponding column number.

Question

Excel Column Number

You have been given a column title as appears in an Excel sheet, return its corresponding column number.

Accepted Answer

Initialize final_ans = 0. Take one character at a time (curr_char = st[i]) and (final_ans = final_ans*26 + curr_char). It is just like binary to decimal conversion. I solved this question very quickly and got enough time to solve next question.

Accepted Answer

The approach which can be used here is similiar to binary to decimal conversion.Suppose we have given string : ABC, the formula is 26 * 26* 1 + 26*2 + 3,so instead of 2 base here is 26. So just traverse given string and calulate the result using formula as decribe above.

int convertToNumber(string input)

{

int result = 0;

for (int i=0;i

{

result *= 26;

result += input[i] - 'A' + 1;

}

return result;

}

Accepted Answer

Base 26 Conversion

The process is very much similar to binary to decimal conversion. In this case, the base of the given system is to be taken as 26. Also, in this system 1 is represented as ‘A’, 2 is represented as ‘B’ and so on till 26 is represented as ‘Z’

For example-

CDA can be converted as 3*26*26 + 4*26 + 1

= 26(3*26 + 4) + 1

= 26(0*26 + 3*26 + 4) + 1

AB can be converted as 1*26 + 2

Space Complexity: O(1)Explanation:

O(1)

As no extra space is required.

Time Complexity: O(n)Explanation:

O(n), where n is the length of the input string.

Since we are traversing each character of string only once.

Top Oracle Software Developer interview questions & answers

Popular interview questions of Software Developer

Top HR questions asked in Oracle Software Developer