ZigZag Conversion

func convert(s string, numRows int) string {

    if numRows == 1{
        return s
    }
    var strList []rune
    strList = []rune(s)
    var res []rune
    gapCount := 2*numRows-2

    for i:=1;i<=numRows;i++{
        start:= i-1
        step := gapCount-((i-1)*2)
        for ;;{
            if start>len(strList)-1{
                break
            }
            if step != 0{
                res = append(res,strList[start])
            }
            start += step
            step = gapCount-step
        }
    }
    return string(res)
}

func convert(s string, numRows int) string {

    if numRows == 1{
        return s
    }
    var strList []rune
    strList = []rune(s)
    var res []rune

    for i:=1;i<=numRows;i++{
        for k,v :=range strList {
            if k%(2*numRows-2) == i-1{
                res = append(res,v)
            }else if k%(2*numRows-2) == 2*numRows-1-i && i != 1 && i != numRows{
                res = append(res,v)
            }
        }
        continue
    }
    return string(res)
}
```