在选择排序上略有改进的排序算法？
在这里，我们将看到对选择排序的一些改进。众所周知，选择排序是通过从数组中选取最小或最大元素并将该元素放置在正确的位置来进行的。在这种方法中，我们希望以两种方式对数组进行排序。在这里，我们将同时获取最大值和最小值，然后从两端对数组进行排序。让我们看看该算法以获得更好的主意。
算法
twoWaySelectionSort(arr,n)
begin
for i := 0, and j := n-1, increase i by 1, and decrease j by 1, until i>=j, do
min := minimum element from index i to j
max := maximum element from index i to j
i_min := index of min
i_max := index of max
exchange the arr[i] and arr[i_min]
if arr[i_min] is same as max, then
swap arr[j] and arr[i_min]
else
swap arr[j] and arr[i_max]
end if
done
end示例
#include<iostream>
using namespace std;
void twoWaySelectionSort(int arr[], int n) {
//i will move from left, and j will move from right
for (int i = 0, j = n - 1; i < j; i++, j--) {
int min = arr[i], max = arr[i];
int i_min = i, i_max = i; //i_min and i_max will hold min and max index respectively
for (int k = i; k <= j; k++) {
if (arr[k] > max) {
max = arr[k];
i_max = k;
} else if (arr[k] < min) {
min = arr[k];
i_min = k;
}
}
swap(arr[i], arr[i_min]); //put the min into the index i
if (arr[i_min] == max)
swap(arr[j], arr[i_min]);
else
swap(arr[j], arr[i_max]);
}
}
main() {
int arr[] = { 25, 45, 14, 10, 23, 29, 65, 21, 78, 96, 30 };
int n = sizeof(arr) / sizeof(arr[0]);
twoWaySelectionSort(arr, n);
cout << "Sorted array: ";
for (int i = 0; i < n; i++)
cout << arr[i] << " ";
}输出结果
Sorted array: 10 14 21 23 25 29 30 45 65 78 96