2013-07-30 20:35 388人阅读
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http://acm.hdu.edu.cn/showproblem.php?pid=4627
The Unsolvable Problem
Time Limit: 2000/1000
MS (Java/Others) Memory Limit: 32768/32768 K
(Java/Others)
Total Submission(s): 230 Accepted
Submission(s): 136
Problem Description
There are many unsolvable problem in the world.It could be
about one or about zero.But this time it is about bigger number.
Given an
integer n(2 <= n <= 109).We should find a pair
of positive integer a, b so that a + b = n and [a, b]
is as large as possible. [a, b] denote the least common multiplier of a,
b.
Input
The first line contains integer T(1<= T<=
10000),denote the number of the test cases.
For each test cases,the first
line contains an integer n.
Output
For each test cases,print the maximum
[a,b] in a line.
标准签到题，先特判n==2的情况，否则若n为奇数，则答案显然是n/2
和 n/2+1，若n为偶数设n=2*k，若k为偶数，则答案为k-1,k+1,否则答案为k-2,k+2。
- #include <iostream>
- #include <string.h>
- #include <stdio.h>
- #include <algorithm>
- #define ll long long
- using namespace std;
- int main()
- {
-
- ll n,ncase;
- cin>>ncase;
- while(ncase--)
- {
- cin>>n;
- if(n==2)
- cout<<1<<endl;
- else
- {
- if(n%2)
- cout<<(n/2)*(n-n/2)<<endl;
- else
- {
- if((n/2)%2==0)
- cout<<(n/2-1)*(n/2+1)<<endl;
- else
- cout<<(n/2-2)*(n/2+2)<<endl;
- }
- }
- }
- return 0;
- }
- 一开始用暴力，唉，挂了，但是为什么是这样呢，想了半天终于明白了。
2013多校联合3 G The Unsolvable Problem（hdu 4627）,布布扣,bubuko.com
2013多校联合3 G The Unsolvable Problem（hdu 4627）
原文：http://www.cnblogs.com/zhaoxinshanwei/p/3619245.html
