烙饼排序

 1 #include <stdio.h>
 2 // print the array
 3 int printArr(int* arr, int length)
 4 {
 5     int i = 0;
 6     for(i=0;i<length;i++)
 7         printf("%d\t",arr[i]);
 8     printf("\n");
 9 }
10 // swap 2 value
11 void swapValue(int *a, int * b)
12 {
13     int temp = 0;
14     temp = *a;
15     *a = *b;
16     *b = temp;
17 }
18 // check whether the array is sorted
19 int isDone(int * arr, int length)
20 {
21     while(--length>=1)
22     {
23         if(arr[length]>arr[length-1])
24             return 0;
25     }
26     return 1;
27 }
28 // find the biggest value‘s index
29 int findMaxIndex(int* arr, int length)
30 {
31     int i = 0;
32     int standBy = arr[0];
33     while(length--)
34     {
35         if(standBy < arr[length])
36         {
37             standBy = arr[length];
38             i = length;
39         }
40     }
41     return i;
42 }
43 // reverse the part of the array from the start position
44 int reversePart(int* arr, int start, int length)
45 {
46     int end = length-1;
47     while(start<=end)
48     {
49         swapValue(&arr[start],&arr[end]);
50         start++;
51         end--;
52     }
53 }
54 // core algorithm
55 // 1. find the biggest value‘s index
56 // 2. check if the index is at the head of the array
57 //    true : enter the next loop
58 //    false : go to 3 step
59 // 3. check if the index is at the end of the array
60 //    true : go to 4 step
61 //    false : reverse the part -- get the biggest value to the end of the array
62 // 4. reverse the selected part of the array
63 // 5. check whether the array is sorted
64 //    true : break the loop
65 //    false : enter the next loop
66 void biscuitSort(int* arr, int length)
67 {
68     int start = 0;
69     int maxIndex = 0;
70     for(start = 0; start < length; start++)
71     {
72         maxIndex = findMaxIndex(arr+start,length-start);
73         if(maxIndex != 0)
74         {
75             if(maxIndex != length-start-1)
76             {
77                 reversePart(arr+start,maxIndex,length-start);
78                 printArr(arr,length);
79             }
80             reversePart(arr+start,0,length-start);
81             printArr(arr,length);
82             if(isDone(arr,length))
83                 break;
84         }
85     }
86 }
87  
88 int main()
89 {
90     int arr[]= {7,1,2,5,4};
91     printArr(arr, sizeof(arr)/sizeof(int));
92     biscuitSort(arr, sizeof(arr)/sizeof(int));
93     return 0;
94 }