寻找旋转有序数组的最小值

#include <iostream>
using namespace std;
int a[]={3,4,5,0,2};//原数组为0 2 3 4 5，旋转后就成了这个
int Partition(int start,int end)
{
	swap(a[7],a[end]);
	int i;
	int record=a[end];
	int leftregion=start;
	for(i=start;i<end;i++)
	{
	  if(a[i]<=record)
	  {
		  if(i!=leftregion)
		  swap(a[i],a[leftregion]);
		  leftregion++;
	  }
	}
	swap(a[leftregion],a[end]);
	return leftregion;
}
int FindMinNumber(int index1,int index2)
{
  int ret=a[index1];
  for(int i=index1;i<=index2;i++)
  {
    if(a[i]<ret)
		ret=a[i];
  }
 return ret;
}
int Rotate(int start,int end)
{
   int index1=start;
   int index2=end;
   int mid;
   while(a[index1]>=a[index2])
   {
      if(index2-index1==1)
		  return a[index2];
	  mid=(index1+index2)/2;
	  if(a[mid]==a[index1]&&a[index1]==a[index2])
		  return FindMinNumber(index1,index2);
      if(a[mid]>=a[index1])
		  index1=mid;
	  else if(a[mid]<=a[index2])
		  index2=mid;

   }
}
int main()
{
	cout<<Rotate(0,4)<<endl;
  return 0;
}