golang binarySearch

func binarySearch(nodes []*node, word Text) (int, bool) {
    start := 0
    end := len(nodes) - 1
 
    // 特例：
    if len(nodes) == 0 {
        // 当slice为空时，插入第一位置
        return 0, false
    }
    compareWithFirstWord := bytes.Compare(word, nodes[0].word)
    if compareWithFirstWord < 0 {
        // 当要查找的元素小于首元素时，插入第一位置
        return 0, false
    } else if compareWithFirstWord == 0 {
        // 当首元素等于node时
        return 0, true
    }
    compareWithLastWord := bytes.Compare(word, nodes[end].word)
    if compareWithLastWord == 0 {
        // 当尾元素等于node时
        return end, true
    } else if compareWithLastWord > 0 {
        // 当尾元素小于node时
        return end + 1, false
    }
 
    // 二分
    current := end / 2
    for end-start > 1 {
        compareWithCurrentWord := bytes.Compare(word, nodes[current].word)
        if compareWithCurrentWord == 0 {
            return current, true
        } else if compareWithCurrentWord < 0 {
            end = current
            current = (start + current) / 2
        } else {
            start = current
            current = (current + end) / 2
        }
    }
    return end, false
}