HDU 3763 CD(二分查找)
Problem Description
Jack and Jill have decided to sell some of their Compact Discs, while they still have some value. They have decided to sell one of each of the CD titles that they both own. How many CDs can Jack and Jill sell?
Neither Jack nor Jill owns more than one copy of each CD.
Input
The input consists of a sequence of test cases. The first line of each test case contains two non-negative integers N and M, each at most one million, specifying the number of CDs owned by Jack and by Jill, respectively. This line is followed by N lines listing the catalog numbers of the CDs owned by Jack in increasing order, and M more lines listing the catalog numbers of the CDs owned by Jill in increasing order. Each catalog number is a positive integer no greater than one billion. The input is terminated by a line containing two zeros. This last line is not a test case and should not be processed.
Output
For each test case, output a line containing one integer, the number of CDs that Jack and Jill both own.
Sample Input
3 3
1
2
3
1
2
4
0 0
Sample Output
2
题目大意：
简单来说就是给你第一个人拥有的CD数目和第二个人用拥有的CD数目，然后分别给出他们的编号，让你统计他们俩有多少张一样编号的CD数目。
#include<stdio.h>
int a[1000005],k;
int main()
{
int n,m,i,sum,h,d,mid;
while(scanf("%d%d",&n,&m)>0&&(n!=0||m!=0))
{
sum=0;
for(i=0;i<n;i++)
scanf("%d",&a[i]);
while(m--)
{
scanf("%d",&k);
h=0;d=n-1;
while(h<=d)
{
mid=(h+d)/2;
if(a[mid]>k)
d=mid-1;
if(a[mid]<k)
h=mid+1;
if(a[mid]==k)
{
sum++;break;
}
}
}
printf("%d\n",sum);
}
}