C language implements two descending series to find a certain number _c language

This article describes the C language to achieve the two descending sequence to find a certain number of methods to share for everyone to use for reference. The specific methods are as follows:

In general, this problem is a very difficult question in the binary search method.

The topics are as follows:

An array is left by a descending sequence of several bits to form, such as {4, 3, 2, 1, 6, 5} is moved 6 by {5, 4, 3, 2, 1, two} to find a number in this array.

The implementation code is as follows:

int array[] = {4, 3, 2, 1, 6, 5};
const int size = sizeof array/sizeof *array;

int findminnumber (int (&array) [size], int start, int last, int dest)
{
 int mid = (Last-start)/2 + start;
   int result;

 if (Start > last) {
 return-1
 }

 if (array[mid] = = dest) {result
 = Mid;
 return result;
 } 

 if (Array[mid] <= Array[start]) {
 if (dest > Array[mid] && dest <=]) {Last
 = Array[start ;
 result = Findminnumber (array, start, last, dest);
 else {
 start = mid + 1;
 result = Findminnumber (array, start, last, dest);
 }
 else if (Array[mid] > Array[start]) {
 if (Dest < Array[mid] && dest >= array[last]) {
 start = mid + 1;
 result = Findminnumber (array, start, last, dest);
 else {Last
 = mid-1;
 result = Findminnumber (array, start, last, dest);
 }

 return result;
}

The results of the program run as shown in the following illustration:

I hope this article is helpful to the learning of C program algorithm design.