这题和剑指offer上的旋转数组的最小值类似,此题应该比那题还简单,因为没有重复的元素。
int bisearch(int *arr,int start,int end,int value)
{
while(start<=end)
{
int mid = (start + end)>>1;
if (arr[mid]==value)
{
return mid;
}
else
{
if (arr[mid]>value)
end = mid -1;
else
start = mid + 1;
}
}
return -1;
}
int search(int A[], int n, int target) {
if (A[0]<A[n-1])
{
return bisearch(A,0,n-1,target);
}
if (n==1&&A[0]==target)
{
return 0;
}
int i=0,j=n-1;
while(i<j)
{
if(A[i]==target)
return i;
if(A[j]==target)
return j;
int mid = (i+j)>>1;
if(A[mid]==target)
return mid;
if (A[i]<A[mid])
{
if (target>A[i]&&target<A[mid])
{
return bisearch(A,i+1,mid-1,target);
}
else
i = mid + 1;
}
else
{
if (target>A[mid]&&target<A[j])
{
return bisearch(A,mid+1,j-1,target);
}
else
j = mid - 1;
}
}
return -1;
}