0001 template <typename T> void Vector<T>::selectionSort(Rank lo, Rank hi) {
0002    while (lo < --hi)
0003       swap(_elem[getMax(lo, hi)], _elem[hi]); //将[hi]与[lo, hi]中的最大者交换
0004 } //selectionSort
0005 
0006 template <typename T> Rank Vector<T>::getMax(Rank lo, Rank hi) {
0007    Rank mx = hi;
0008    while (lo < hi--) //逆向扫描
0009       if (_elem[hi] > _elem[mx]) //且严格比较
0010          mx = hi; //故能在max有多个时保证后者优先，进而保证selectionSort稳定
0011    return mx;
0012 } //getMax