itoa.nim

proc itoa(n:int):string =
    var num = if n<0: -n else: n
    var i = 0
    result = ""
    
    while num > 0:
        result.add(char(48 + num mod 10))
        num = num div 10
        inc i # inc char count 

    if n < 0: 
        result.add('-')
        inc i
    num = 0
    i = i-1
    while num < i:
        swap(result[num], result[i])
        dec i
        inc num