HDU 5924 Mr. Frog’s Problem

Problem Description

One day, you, a clever boy, feel bored in your math class, and then fall asleep without your control. In your dream, you meet Mr. Frog, an elder man. He has a problem for you.

He gives you two positive integers A and B, and your task is to find all pairs of integers (C, D), such that A≤C≤B,A≤D≤B and A/B+B/A≤C/D+D/C

Input

first line contains only one integer T (T≤125), which indicates the number of test cases. Each test case contains two integers A and B (1≤A≤B≤1018).

Output

For each test case, first output one line “Case #x:”, where x is the case number (starting from 1).

Then in a new line, print an integer s indicating the number of pairs you find.

In each of the following s lines, print a pair of integers C and D. pairs should be sorted by C, and then by D in ascending order.

Sample Input

2
10 10
9 27

Sample Output

Case #1:
1
10 10
Case #2:
2
9 27
27 9

题目大意：

输入一个数n表示接下来有n组测试数据，输入两个数A,B，求A≤C≤B,A≤D≤B，且A/B+B/A≤C/D+D/C；由于A,B是区间的两个端点，所以A/B + B/A 已经就是最大值了。所以当A==B 时答案就是A，B；当不相等时，答案为A,B和B,A；这道题只需注意因为A,B过大需用字符串存储即可。

C++

#include<iostream>#include<cstdio>#include<string>using namespace std;int main(){    int a,d,e,f;    string b,c;    scanf("%d",&a);    e=1;    while(a--)    {        cin>>b>>c;        if(b==c)        {            cout<<"Case #"<<e<<":"<<endl;            cout<<"1"<<endl;            cout<<b<<" "<<c<<endl;            e++;        }        else        {            cout<<"Case #"<<e<<":"<<endl;            cout<<"2"<<endl;            cout<<b<<" "<<c<<endl;            cout<<c<<" "<<b<<endl;            e++;        }    }    return 0;}