12、【查找算法】插值查找

 1 //插值查找
 2 #include <iostream>
 3 #include <stdlib.h>
 4 #include <ctime>
 5 
 6 using namespace std;
 7 
 8 #define MAX 100
 9 //数组输入
10 void input(int *arr)
11 {
12     srand((unsigned)time(NULL));
13     for(int i = 0; i < MAX; i++)
14     {
15         arr[i] = rand()%100;
16     }
17 }
18 //数组输出
19 void output(int *arr)
20 {
21     for(int i = 0; i < MAX; i++)
22     {
23         cout << arr[i] << "  ";
24         if(0 == i % 10)
25             cout << endl;
26     }
27     cout << endl;
28 }
29 //快速排序
30 void quickSort(int *arr, int l, int h)
31 {
32     if(l < h)
33     {
34         int low, high, tmp;
35         low = l;
36         high = h;
37 
38         tmp = arr[l];//选择基准值
39         //将数组按照基准值分为两部分
40         while(low < high)
41         {
42             while(low < high && arr[high] > tmp)
43                 high--;
44             if(low < high)
45                 arr[low++] = arr[high];
46             while(low < high && arr[low] < tmp)
47                 low++;
48             if(low < high)
49                 arr[high--] = arr[low];
50         }
51         arr[low] = tmp;
52         //递归排序
53         quickSort(arr, l, low-1);
54         quickSort(arr, low+1, h);
55     }
56 }
57 //插值查找
58 int insertionSearch(int *arr, int value, int low, int high)
59 {
60     //相比
61     int mid = low + ((value - arr[low])/(arr[high] - arr[low]))*(high - low);
62 
63     if(arr[mid] == value)
64         return mid;
65     if(arr[mid] > value)
66         return insertionSearch(arr, value, low, mid-1);
67     if(arr[mid] < value)
68         return insertionSearch(arr, value, mid+1, high);
69 }
70 
71 int main()
72 {
73     int x, pos, num[MAX];
74     input(num);
75 
76     cout << "sort before:" << endl;
77     output(num);
78     quickSort(num, 0, MAX-1);
79     cout << "sort after:" << endl;
80     output(num);
81 
82     cout << "Enter find num : ";
83     cin >> x;
84 
85     pos = insertionSearch(num, x, 0, MAX-1);
86 
87     if(pos)
88         cout << "OK!" << x << "is found in pos : " << pos << endl;
89     else
90         cout << "Sorry!" << x << "is not found in num" << endl;
91 
92     return 0;
93 }