30.用折半查找法求一个数？ 数组a已按从小到大的顺序排列

while((!sign) && (bott <= top))
{
    mid=(bott + top)/2;
     if(number ==a[mid])
    {
        local=mid;
        printf(“the local is %d\n”,local);
        printf(“the number is%d\n”, number);
        sign =true;
}
else if(number