算法题（如何从列标题中查找Excel列号（）） _数据结构

本文概述

C ++
Java
Python3
C#

我们已经讨论过从列号转换为Excel列名。在这篇文章中, 讨论了反向。
给定列标题(如Excel工作表中所示), 返回其对应的列号。

columncolumn number A-> 1 B-> 2 C-> 3 ... Z-> 26 AA -> 27 AB -> 28

例子：

Input: A Output: 1 A is the first column so the output is 1.Input: AA Output: 27 The columns are in order A, B, ..., Y, Z, AA .. So, there are 26 columns after which AA comes.

方法：
该过程类似于二进制到十进制的转换。
例如, 要转换AB, 公式为26 * 1 + 2。
再举一个例子

To convert CDA, 3*26*26 + 4*26 + 1 = 26(3*26 + 4) + 1 = 26(0*26 + 3*26 + 4) + 1

因此, 这非常类似于将二进制数转换为十进制(将基数保持为26)。
将输入作为字符串, 然后从左到右遍历输入字符串, 并计算结果, 如下所示：

result = 26*result + s[i] - 'A' + 1

.
结果将是

文章图片
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C ++

// C++ program to return title to result // of excel sheet. #include < bits/stdc++.h> using namespace std; // Returns resul when we pass title. int titleToNumber(string s) { // This process is similar to // binary-to-decimal conversion int result = 0; for ( const auto & c : s) { result *= 26; result += c- 'A' + 1; }return result; }// Driver function int main() { cout < < titleToNumber( "CDA" ) < < endl; return 0; }

Java

// Java program to return title // to result of excel sheet. import java.util.*; import java.lang.*; class GFG {// Returns resul when we pass title. static int titleToNumber(String s) { // This process is similar to // binary-to-decimal conversion int result = 0 ; for ( int i = 0 ; i < s.length(); i++) { result *= 26 ; result += s.charAt(i) - 'A' + 1 ; } return result; }// Driver Code public static void main (String[] args) { System.out.print(titleToNumber( "CDA" )); } }// This code is contributed // by Akanksha Rai(Abby_akku)

Python3

# Python program to return title to result # of excel sheet. # Returns resul when we pass title. def titleToNumber(s): # This process is similar to binary-to- # decimal conversion result = 0 ; for B in range ( len (s)): result * = 26 ; result + = ord (s[B]) - ord ( 'A' ) + 1 ; return result; # Driver function print (titleToNumber( "CDA" )); # This code contributed by Rajput-Ji

// C# program to return title // to result of excel sheet. using System; class GFG {// Returns resul when we pass title. public static int titleToNumber( string s) { // This process is similar to // binary-to-decimal conversion int result = 0; for ( int i = 0; i < s.Length; i++) { result *= 26; result += s[i] - 'A' + 1; } return result; }// Driver Code public static void Main( string [] args) { Console.Write(titleToNumber( "CDA" )); } }// This code is contributed by Shrikant13

输出如下：