对分查找(Binary Search)

已知一个有序序列，和一个整数X，插入X在合适的地方

int BinarySearch(int A[], int X, int N)
{
int low=0, high=N-1, mid;
while(low<=high)
{
mid = (high - low)/2;
if(X > A[mid])
low = mid + 1;
else if(X > mid)
high = mid - 1;
else
return mid;
}
while -1;
}