冒泡排序、选择排序、插入排序、快速排序算法的时间性能分析（java实现）

冒泡排序、选择排序、插入排序、快速排序算法的时间性能分析（java实现）

public class Sort

{

public void swap(int a[], int i, int j)

{

int tmp = a[i];

a[i] = a[j];

a[j] = tmp;

}

public int partition(int a[], int low, int high)

{

int pivot, p_pos, i;

p_pos = low;

pivot = a[p_pos];

for (i = low + 1; i <= high; i++)

{

if (a[i] > pivot)

{

p_pos++;

swap(a, p_pos, i);

}

}

swap(a, low, p_pos);

return p_pos;

}

public void quicksort(int a[], int low, int high)

{

int pivot;

if (low < high)

{

pivot = partition(a, low, high);

quicksort(a, low, pivot - 1);

quicksort(a, pivot + 1, high);

}

}

public static void main(String args[])

{

int vec[] = new int[] { 77, 19, 27, -9, 19, 34 };

int temp;

System.out.println("对37, 47, 23, -5, 19, 56进行排序");

// 选择排序法(Selection Sort)

long begin = System.currentTimeMillis();

for (int k = 0; k < 1000000; k++)

{

for (int i = 0; i < vec.length; i++)

{

for (int j = i; j < vec.length; j++)

{

if (vec[j] > vec[i])

{

temp = vec[i];

vec[i] = vec[j];

vec[j] = temp;

}

}

}

}

long end = System.currentTimeMillis();

System.out.println(); //另起一行

System.out.println("选择法用时为：" + (end - begin) + "/n排序结果：");

// 打印排序好的结果

for (int i = 0; i < vec.length; i++)

{

System.out.print(vec[i]);

System.out.print(" ");

}

// 冒泡排序法(Bubble Sort)

begin = System.currentTimeMillis();

for (int k = 0; k < 1000000; k++)

{

for (int i = 0; i < vec.length; i++)

{

for (int j = i; j < vec.length - 1; j++)

{

if (vec[j + 1] > vec[j])

{

temp = vec[j + 1];

vec[j + 1] = vec[j];

vec[j] = temp;

}

}

}

}

end = System.currentTimeMillis();

System.out.println(); //另起一行

System.out.println("冒泡法用时为：" + (end - begin)+ "/n排序结果：");

// 打印排序好的结果

for (int i = 0; i < vec.length; i++)

{

System.out.print(vec[i]);

System.out.print(" ");

}

// 插入排序法(Insertion Sort)

begin = System.currentTimeMillis();

for (int k = 0; k < 1000000; k++)

{

for (int i = 1; i < vec.length; i++)

{

int j = i;

while (vec[j - 1] < vec[i])

{

vec[j] = vec[j - 1];

j--;

if (j <= 0)

{

break;

}

}

vec[j] = vec[i];

}

}

end = System.currentTimeMillis();

System.out.println(); //另起一行

System.out.println("插入法用时为：" + (end - begin)+ "/n排序结果：");

// 打印排序好的结果

for (int i = 0; i < vec.length; i++)

{

System.out.print(vec[i]);

System.out.print(" ");

}

// 快速排序法(Quick Sort)

Sort s = new Sort();

begin = System.currentTimeMillis();

for (int k = 0; k < 1000000; k++)

{

s.quicksort(vec, 0, 5);

}

end = System.currentTimeMillis();

System.out.println(); //另起一行

System.out.println("快速法用时为：" + (end - begin)+ "/n排序结果：");

// 打印排序好的结果

for (int i = 0; i < vec.length; i++)

{

System.out.print(vec[i]);

System.out.print(" ");

}

}

}