算法-字符串

+ 翻转单词顺序(简单)

func reverseWords(s string) string {

    s = strings.TrimSpace(s)

    j := len(s)-1
    i := j
    res := []string{}
    for i >= 0 {
        for i >= 0 &&  s[i] != ' '{
            i--
        }
        res = append(res, s[i+1:j+1])
        for i >= 0 &&  s[i] == ' '{
            i--
        }
        j = i

    }

    return strings.Join(res," ")
}

+ 罗马数字转整数(简单)

func romanToInt(s string) int {
  res := map[string]int{
        "I": 1,
        "V": 5,
        "X": 10,
        "L": 50,
        "C": 100,
        "D": 500,
        "M": 1000,
    }
    sum := 0
    for i := 0; i < len(s); i++ {
        val := res[string(s[i])]
        if i < len(s)-1 && val < res[string(s[i+1])] {
            sum -= val
        } else {
            sum += val
        }
    }
    return sum
}