常见的排序算法
1 #include<iostream>
2 using namespace std;
3
4 void quick(int a[],int left, int right)
5 {
6 if (left == right)
7 return;
8 int index = (right + left + 1) / 2;
9 int temp;
10 temp = a[index];
11 a[index] = a[right];
12 a[right] = temp;
13 int p = 0;
14 int prev = -1;
15 while (p != right)
16 {
17 if (a[p] >= a[right])
18 {
19 if ((p - prev) != 1)
20 {
21 prev++;
22 temp = a[p];
23 a[p] = a[prev];
24 a[prev] = temp;
25 }
26 else
27 prev++;
28 }
29 p++;
30 }
31 prev++;
32 temp = a[p];
33 a[p] = a[prev];
34 a[prev] = temp;
35 if(prev!=left)
36 quick(a, left, prev-1);
37 if(prev!=right)
38 quick(a, prev+1, right);
39 }
40
41 int main()
42 {
43 int n,temp;
44 cout << "请输入数组个数：" << endl;
45 cin >> n;
46 int *a = new int [n];
47 for (int i = 0; i < n; i++)
48 {
49 cin >> temp;
50 a[i] = temp;
51 }
52
53 //冒泡排序-从小到大
54 for(int i=0;i<n-1;i++)
55 for(int j=0;j<n-1-i;j++)
56 if (a[j] > a[j + 1])
57 {
58 temp = a[j];
59 a[j] = a[j + 1];
60 a[j + 1] = temp;
61 }
62 for (int i = 0; i < n; i++)
63 cout << a[i];
64 cout << endl;
65
66 //选择排序-从大到小
67 int i,j,max;
68 for (i = 0; i < n - 1; i++)
69 {
70 max = i;
71 for (j = i; j < n; j++)
72 if (a[j] > a[max])
73 max = j;
74 if (max != i)
75 {
76 temp = a[i];
77 a[i] = a[max];
78 a[max] = temp;
79 }
80 }
81 for (int i = 0; i < n; i++)
82 cout << a[i];
83 cout << endl;
84
85 //插入排序-从小到大
86 for (i = 1; i < n; i++)
87 {
88 temp = a[i];
89 j = i - 1;
90 while (j >= 0 && a[j] > temp)
91 {
92 a[j + 1] = a[j];
93 j--;
94 }
95 a[j + 1] = temp;
96 }
97 for (int i = 0; i < n; i++)
98 cout << a[i];
99 cout << endl;
100
101 //快速排序-从大到小
102 quick(a,0, n - 1);
103 for (int i = 0; i < n; i++)
104 cout << a[i];
105 cout << endl;
106
107 delete[] a;
108 system("pause");
109 return 0;
110
111 }
