a1 style column logic

bijective base26を経由してconverterを使用可能。

converter

`number`===typeof v

1. declare this.number
this.number=v

2. declare this.alphabet
this.alphabet=``

3. loop
for(let i=v;-1<i;i=(i/26>>>0)-1)

4. set this.alphabet
this.alphabet=String.fromCharCode(97+i%26)+this.alphabet

`number`!==typeof v

1. declare this.alphabet
this.alphabet=v

2. declare this.number
this.number=0

3. loop
for(let i=0;i<v.length;i++)

4. set this.number
this.number=this.number*26+v.charCodeAt(i)-96

5. set this.number
this.number--