二分算法

int search4(int array[], int n, int v){    int left, right, middle;    left = -1, right = n;    while (left + 1 != right)    {        middle = left + （right － left) / 2;        if (array[middle] < v)        {            left = middle;        }        else        {            right = middle;        }    }    if (right >= n || array[right] != v)    {        right = -1;    }    return right;}