文章目录
一、Design Tutorial: Learn from Math
总结
一、Design Tutorial: Learn from Math
本题链接：Design Tutorial: Learn from Math
题目：
A. Design Tutorial: Learn from Math
time limit per test1 second
memory limit per test256 megabytes
inputstandard input
outputstandard output
One way to create a task is to learn from math. You can generate some random math statement or modify some theorems to get something new and build a new task from that.
For example, there is a statement called the “Goldbach’s conjecture”. It says: “each even number no less than four can be expressed as the sum of two primes”. Let’s modify it. How about a statement like that: “each integer no less than 12 can be expressed as the sum of two composite numbers.” Not like the Goldbach’s conjecture, I can prove this theorem.
You are given an integer n no less than 12, express it as a sum of two composite numbers.
Input
The only line contains an integer n (12 ≤ n ≤ 1e6).
Output
Output two composite integers x and y (1 < x, y < n) such that x + y = n. If there are multiple solutions, you can output any of them.
Examples
input
12
output
4 8
input
15
output
6 9
input
23
output
8 15
input
1000000
output
500000 500000
Note
In the first example, 12 = 4 + 8 and both 4, 8 are composite numbers. You can output "6 6" or "8 4" as well.
In the second example, 15 = 6 + 9. Note that you can’t output "1 14" because 1 is not a composite number.
本博客给出本题截图：
题意：输入一个大于等于12的数，把它拆成两个合数并输出
AC代码
#include <iostream> using namespace std; int main() { int n; cin >> n; if (n % 2) cout << 9 << ' ' << n - 9; else cout << 4 << ' ' << n - 4; return 0; }
总结
水题，不解释
