條件:數組
思想:數組第一個元素與餘下的元素相比較,如果滿足比較條件,兩者互換,以此類推;
比較次數:N*N/2
次比較,N次交換;
特點:1.運行時間與輸入無關;2.數據移動是最小的;
C++實現:
const int N = 10;
void selectionSort()
{
int a[N];
srand(time(NULL));
for (int i = 0; i < N; ++i)
{
a[i] = rand() % 100; // 100 以內的數
}
// 打印輸出隨機數組
cout << "選擇排序前的數組:" << endl;
for (int i = 0; i < N; ++i)
{
cout << setw(3) << a[i];
}
cout << endl;
for (int i = 0; i < N; ++i)
{
int temp = i;
for (int j = i + 1; j < N; ++j)
{
if (a[temp] < a[j])
{
temp = j;
}
}
if (temp != i)
{
int tempArr = a[temp];
a[temp] = a[i];
a[i] = tempArr;
}
}
cout << "選擇排序後的數組:" << endl;
for (int i = 0; i < N; ++i)
{
cout << setw(3) << a[i];
}
cout << endl;
}