HDU 2141（搜索题，二分）

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Can you find it?

Time Limit: 10000/3000 MS (Java/Others) Memory Limit: 32768/10000 K (Java/Others)
Total Submission(s): 1836 Accepted Submission(s): 400

Problem Description

Give you three sequences of numbers A, B, C, then we give you a number X. Now you need to calculate if you can find the three numbers Ai, Bj, Ck, which satisfy the formula Ai+Bj+Ck = X.

Input

There are many cases. Every data case is described as followed: In the first line there are three integers L, N, M, in the second line there are L integers represent the sequence A, in the third line there are N integers represent the sequences B, in the forth line there are M integers represent the sequence C. In the fifth line there is an integer S represents there are S integers X to be calculated. 1<=L, N, M<=500, 1<=S<=1000. all the integers are 32-integers.

Output

For each case, firstly you have to print the case number as the form "Case d:", then for the S queries, you calculate if the formula can be satisfied or not. If satisfied, you print "YES", otherwise print "NO".

Sample Input

3 3 31 2 31 2 31 2 331410

Sample Output

Case 1:NOYESNO
有人评论说是WA的，看来代码写的不够好，几年没接触算法的东西了。
#include <iostream>#include <algorithm>using namespace std;#define N 505__int64 ab[N*N];int num;int search(__int64 x){int f=0,l=num-1;int mid;while(f<=l){mid=(f+l)/2;if(ab[mid]==x)return 1;else if(ab[mid]<x)f=mid+1;elsel=mid-1;}return 0;}int main(){int n,m,l,flag=0,s,i,j;__int64 a[N],b[N],c[N],x;while(scanf("%d%d%d",&n,&m,&l)!=EOF){flag++;num=0;for(i=0;i<n;i++)scanf("%I64d",&a[i]);for(i=0;i<m;i++)scanf("%I64d",&b[i]);for(i=0;i<l;i++)scanf("%I64d",&c[i]);for(i=0;i<n;i++)for(j=0;j<m;j++)ab[num++]=a[i]+b[j];sort(ab,ab+num);sort(c,c+l);scanf("%d",&s);printf("Case %d:/n",flag);while(s--){scanf("%I64d",&x);if(x<ab[0]+c[0] || x>ab[num-1]+c[l-1])printf("NO/n");else{int p;for(j=0;j<l;j++){p=x-c[j];if(search(p)){printf("YES/n");break;}}if(j==l)printf("NO/n");}}}return 0;}