二分查找（递归与非递归）

int search(int *a, int target, int p, int r)
{
if (p <= r)
{
int mid;

mid = (p + r) / 2;
if (*(a + mid) == target)
return 1;
else if (*(a + mid) > target)
return search(a, target, p, mid - 1);
else
return search(a, target, mid + 1, r);
}
return 0;
}

int search(int *a, int target, int p, int r)
{
int mid;

while (p <= r)
{
mid = (p + r) / 2;
if (*(a + mid) == target)
return 1;
else if (*(a + mid) > target)
r = mid - 1;
else
p = mid + 1;
}

return 0;
}