Codeforces Round #440 div2 C. Maximum splitting
来源:互联网 发布:税收数据质量管理 编辑:程序博客网 时间:2024/05/27 09:47
You are given several queries. In the i-th query you are given a single positive integer ni. You are to represent ni as a sum of maximum possible number of composite summands and print this maximum number, or print -1, if there are no such splittings.
An integer greater than 1 is composite, if it is not prime, i.e. if it has positive divisors not equal to 1 and the integer itself.
The first line contains single integer q (1 ≤ q ≤ 105) — the number of queries.
q lines follow. The (i + 1)-th line contains single integer ni (1 ≤ ni ≤ 109) — the i-th query.
For each query print the maximum possible number of summands in a valid splitting to composite summands, or -1, if there are no such splittings.
112
3
268
12
3123
-1-1-1
12 = 4 + 4 + 4 = 4 + 8 = 6 + 6 = 12, but the first splitting has the maximum possible number of summands.
8 = 4 + 4, 6 can't be split into several composite summands.
1, 2, 3 are less than any composite number, so they do not have valid splittings.
题意 将一个数分为若干个合数 求出最多可以有多少个
例
4 》 4 = 1(本身也是合数)
5 = -1(本身不是合数)
6 》 6 = 1
7 = -1
8 》 4,4 = 2
9 》 9 = 1
19 》 4,6,9 = 3
小于12的数特判
对于大于等于12的数n:
找到的规律是 让n对最小的合数4取余
n%4==0 输出n/4
n%4==1,1与两个4结合成9 也就是输出n/4-1
n%4==2,2与一个4结合成6,也就是输出n/4
n%4==3,三拆为1+2,1与两个结合为9,2与一个4结合为6,也就是输出n/4-1
#include <cstdio>#include <cstring>#include <string>#include <iostream>#include <algorithm>using namespace std;int main(){ int n, m; scanf("%d", &n); for (int i = 0; i < n; i ++) { scanf("%d", &m); if (m == 1 || m == 2 || m == 3 || m == 5 || m == 7 || m == 11) { printf("-1\n"); } else if (m % 4 == 0) { printf("%d\n", m / 4); } else if (m % 4 == 1 || m % 4 == 3) { printf("%d\n", m / 4 - 1); } else if (m % 4 == 2) { printf("%d\n", m / 4); } }}
- Codeforces Round #440 div2 C. Maximum splitting
- Codeforces Round #440 C. Maximum splitting
- 【Codeforces Round #440 (Div. 2) C】 Maximum splitting
- Codeforces Round #440 (Div. 2)C. Maximum splitting
- Codeforces Round #440 (Div. 2) C. Maximum splitting
- C. Maximum splitting--codeforces
- codeforces 870C Maximum splitting
- codeforces 870C. Maximum splitting
- CodeForces 872C Maximum splitting
- Codeforces Round #440 (Div. 1) A. Maximum splitting
- Codeforces Round #440 (Div. 2,)-数学&规律- Maximum splitting
- Codeforces 872 C Maximum splitting(规律)
- Codeforces 872C Maximum splitting【思维】
- Codeforces Round #440 div2 B Maximum of Maximums of Minimums
- Codeforces round 181 div2 C
- codeforces div2 round#231 C
- codeforces div2 round#230 C
- Codeforces - Round.313.Div2.C
- angular制作购物车
- RecyclerView
- 购物车综合练习题angular js
- HDU 5943 Kingdom of Obsession(二分图匹配+数论)
- 原购物车只有删除和查询
- Codeforces Round #440 div2 C. Maximum splitting
- 竞赛反思
- cocos2d-js 3.0 RC0 手动绑定 C++调用js,js调用C++ jsbinding
- 表单验证
- 表格渲染(删除查询)
- 注册界面模拟,判断邮箱是否符合格式,密码是都符合格式
- 掷骰子
- 51Nod 1444 破坏道路(最短路+枚举)
- 【LeetCode】Binary Tree Preorder Traversal 二叉树的前序遍历(3种方法)- Easy+