Synap apply

gistfile1.coffee

log = (input) ->
    Math.log(input) / Math.log(26)
getColName = (input) ->
  temp = input
  char = ''
  result = ''

  # temp -= temp / temp^power
  # console.log power

  i = 3

  power = Math.floor(log(temp))
  loop
    n = Math.pow(26, power) # 제곱수
    k = Math.floor(temp/n) # 계수
    temp -= k*n # 나머지
    # console.log input, temp, power, k, n
    # XXX => 진법 계산이랑 똑같잖아 ㅁ니어ㅏㄹㅁ니어란ㅁ이ㅏㅓㄹ


    break unless power--

gistfile2.js

function getAlphaName1(input) {
    var ret = '';
    var div = input;
    var table = [''] // 0 index 채움
    for(var i = 0; i < 26; i++) {
        table.push(String.fromCharCode(i+65))
    }

    while (div > 0) {
      mod = div%26
      div = parseInt(div/26)
      if (mod === 0) {
        div--
        mod = 26
      }
      
      ret = table[mod]+ret
    }

    return ret;
}

gistfile3.js

function getAlphaName3(input) {
    //input--; //0-based index
    var i = 0;
    var base26 = input.toString(26);
    var len = base26.length;
    var column = '';
    var code = 0;

    for(i = 0; i < len; i++) {
        code = parseInt(base26[i], 10) + 65
        column += String.fromCharCode(code)
    }
    return column;
}