二分查找离左边元素最近的（可以等于）

int compare(const void *a,const void *b)
{return *(int *)a-*(int *)b;
}
//二分查找离元素（可以等于）
int bi_search(int num[10], int len, int target)
{
<span style="white-space:pre">	</span>int begin = 0;
<span style="white-space:pre">	</span>int end = len-1;<span style="white-space:pre">	</span>
<span style="white-space:pre">	</span>while(begin<end)
<span style="white-space:pre">	</span>{
<span style="white-space:pre">		</span>int mid = (begin+end)/2;
<span style="white-space:pre">		</span>cout<<mid<<" "<<target<<endl;
<span style="white-space:pre">		</span>cout<<mid<<" "<<len-1<<endl;
<span style="white-space:pre">		</span>//最近的一个
<span style="white-space:pre">		</span>if(num[mid]==target)
<span style="white-space:pre">			</span>return mid;
<span style="white-space:pre">		</span>else if(num[mid]>target)
<span style="white-space:pre">			</span>end = mid-1;
<span style="white-space:pre">		</span>else
<span style="white-space:pre">			</span>begin = mid+1;
<span style="white-space:pre">	</span>}
<span style="white-space:pre">	</span>cout<<"begin:"<<begin<<"end:"<<end<<endl;
<span style="white-space:pre">	</span>return end;
}
void main()
{int num[10]={11,35,65,25,79,54,34,66,92,30};qsort(num,10,sizeof(int),compare);for(int i=0;i<10;i++)cout<<num[i]<<" ";cout<<endl;int index = bi_search(num, 10, 36);cout<<index<<endl;
}