字符串按相似度排序

int calcDistance(const QString& source, const QString& target)
{
    int n = source.length();
    int m = target.length();

    if (m == 0) return n;
    if (n == 0) return m;

    QVector <QVector <int>> matrix(n + 1);
    for (int i = 0; i <= n; i++) matrix[i].resize(m + 1);
    for (int i = 1; i <= n; i++) matrix[i][0] = i;
    for (int i = 1; i <= m; i++) matrix[0][i] = i;

    for (int i = 1; i <= n; i++)
    {
        const QChar si = source.at(i - 1);

        for (int j = 1; j <= m; j++)
        {
            const QChar dj = target.at(j - 1);
            int cost;

            if (si == dj)
                cost = 0;
            else
                cost = 1;

            const int above = matrix[i - 1][j] + 1;
            const int left = matrix[i][j - 1] + 1;
            const int diag = matrix[i - 1][j - 1] + cost;
            matrix[i][j] = std::min(above, std::min(left, diag));
        }
    }

    return matrix[n][m];
}

struct YxObjectLessThan {
    QString target;
    YxObjectLessThan(const QString& target_) {
        target = target_;
    }
    bool operator()(const QVariantMap& a, const QVariantMap& b) const {
        QString na = a.value("yxmc", "").toString();
        QString nb = b.value("yxmc", "").toString();
        int da = calcDistance(na, target);
        int db = calcDistance(nb, target);
        return da < db;
    }
};

//用法
std::sort(m_dataList.begin(), m_dataList.end(), YxObjectLessThan(val));