[原创]HDU 1796 How many integers can you find [容斥定理] 【组合数学】
[原创]HDU 1796 How many integers can you find [容斥定理] 【组合数学】
2017-02-11 12:49:25 Tabris_ 阅读数:360
博客爬取于2020-06-14 22:41:40
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https://blog.csdn.net/qq_33184171/article/details/54982226
题目连接:http://acm.hdu.edu.cn/showproblem.php?pid=1796
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看详情——《IJCAI 2017 口碑商家客流量预测大赛》
How many integers can you find
Time Limit: 12000/5000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 7728 Accepted Submission(s): 2281
Problem Description
Now you get a number N, and a M-integers set, you should find out how many integers which are small than N, that they can divided exactly by any integers in the set. For example, N=12, and M-integer set is {2,3}, so there is another set {2,3,4,6,8,9,10}, all the integers of the set can be divided exactly by 2 or 3. As a result, you just output the number 7.
Input
There are a lot of cases. For each case, the first line contains two integers N and M. The follow line contains the M integers, and all of them are different from each other. 0< N<2^31,0< M<=10, and the M integer are non-negative and won’t exceed 20.
Output
For each case, output the number.
Sample Input
12 2
2 3
Sample Output
7
Author
wangye
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题目大意:
求小于n的能够被集合中任意数字整除的数的个数
解题思路:
容斥原理入门题,
实现很好实现 可以状压搞,也可以dfs,但是发现dfs明显要块与状压啊。。
附本题代码
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状压枚举形式 655ms;
1 |
|
dfs形式 202ms
1 | int n,m; |