C语言实现两个递减数列中寻找某一个数

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 <= array[start]) {
 last = mid - 1;
 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;
}