A8036 | Pentagon
时间限制1s
内存限制256MB
通过 / 提交0/0
题目描述
According to the last order issued by the president of Berland every city of the country must have its own Ministry Defense building (their own Pentagon). A megapolis Berbourg was not an exception. This city has $n$ junctions, some pairs of which are connected by two-way roads. Overall there are $m$ roads in the city, no more than one between each pair of junctions.
At the moment choosing a location place for Pentagon in Berbourg is being discussed. It has been decided that Pentagon should cover the territory of five different junctions which are joined into a cycle by roads. In the order to build Pentagon a special wall will be built along the roads (with high-tension razor, high-voltage wire and other attributes). Thus, the number of possible ways of building Pentagon in the city is equal to the number of different cycles at lengths of 5, composed of junctions and roads.
Your task is to prints the number of ways of building Pentagon in Berbourg. Only well-optimized solutions will be accepted. Please, test your code on the maximal testcase.
At the moment choosing a location place for Pentagon in Berbourg is being discussed. It has been decided that Pentagon should cover the territory of five different junctions which are joined into a cycle by roads. In the order to build Pentagon a special wall will be built along the roads (with high-tension razor, high-voltage wire and other attributes). Thus, the number of possible ways of building Pentagon in the city is equal to the number of different cycles at lengths of 5, composed of junctions and roads.
Your task is to prints the number of ways of building Pentagon in Berbourg. Only well-optimized solutions will be accepted. Please, test your code on the maximal testcase.
输入格式
The first line contains two integers $n$ and $m$ ( $1<=n<=700;0<=m<=n·(n-1)/2$ ), where $n$ represents the number of junctions and $m$ is the number of roads in the city. Then follow $m$ lines containing the road descriptions, one in each line. Every road is set by a number of integers $a_{i},b_{i}$ ( $1<=a_{i},b_{i}<=n;a_{i}≠b_{i}$ ), where $a_{i}$ and $b_{i}$ represent the numbers of junctions, connected by the road. The junctions are numbered from 1 to $n$ . It is not guaranteed that from any junction one can get to any other one moving along the roads.
输出格式
Print the single number which represents the required number of ways. Please, do not use %lld specificator to read or write 64-bit integers in C++. It is preffered to use cout (also you may use %I64d).
输入输出样例
输入 #1
5 5 1 2 2 3 3 4 4 5 5 1
输出 #1
1
输入 #2
5 10 1 2 1 3 1 4 1 5 2 3 2 4 2 5 3 4 3 5 4 5
输出 #2
12
暂无题解
C++ 编辑器
输入
输出
可保存默认模板;新题优先使用已保存模板。
当前快捷键仅展示,暂不支持修改。
- 撤销
Ctrl / ⌘ + Z - 重做
Ctrl / ⌘ + Y - 查找
Ctrl / ⌘ + F - 全选
Ctrl / ⌘ + A - 复制
Ctrl / ⌘ + C - 剪切
Ctrl / ⌘ + X - 粘贴
Ctrl / ⌘ + V - 自动排版
工具栏排版按钮 - 草稿保存
编辑时自动保存到本机
历史
提交记录
状态说明时间源码
AI
作答助手
你好,我是作答助手。可以问思路、复杂度、样例含义或代码报错原因;不会直接给出完整 AC 代码。
确定要清空代码吗?
提交通过
评测结果:Accepted