Discription Number theory is interesting, while this problem is boring. Here is the problem. Given an integer sequence a 1, a 2, …, a n, let S(i) = {j|1<=j<i, and a j is a multiple of a i}. If S(i) is not empty, let f(i) be the maximum integer in S(…

pid=4961" target="_blank" style="">题目链接:hdu 4961 Boring Sum 题目大意:给定ai数组; 构造bi, k=max(j|0<j<i,aj%ai=0), bi=ak; 构造ci, k=min(j|i<j≤n,aj%ai=0), ci=ak; 求∑i=1nbi∗ci 解题思路:由于ai≤105,所以预先处理好每一个数的因子,然后在处理bi,ci数组的时候,每次遍历一个数.就将其全部的…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4961 Problem Description Number theory is interesting, while this problem is boring. Here is the problem. Given an integer sequence a1, a2, -, an, let S(i) = {j|1<=j<i, and aj is a multiple of ai}. If S…

Boring Sum Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 698    Accepted Submission(s): 346 Problem Description Number theory is interesting, while this problem is boring. Here is the proble…

题目链接 题意:给你一个数组,让你生成两个新的数组,A要求每个数如果能在它的前面找个最近的一个是它倍数的数,那就变成那个数,否则是自己,C是往后找,输出交叉相乘的和 分析: 这个题这种做法是O(n*sqrt(n))的复杂度,极限数据绝对会超时,但是这个题的数据有点水,所以可以过. 用vis[i]数组表示离数字 i  最近的倍数那个数在a[]中的位置,因为所有数字范围在1--100000所以可行 ,正着扫一遍,每次找到当前的数的除数,同时把除数覆盖位置,把 /除数 的数也覆盖位置. 倒着也是一样,…

Boring Sum Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 814 Accepted Submission(s): 390 Problem Description Number theory is interesting, while this problem is boring. Here is the problem. Giv…

HDOJ(HDU).1258 Sum It Up (DFS) [从零开始DFS(6)] 点我挑战题目 从零开始DFS HDOJ.1342 Lotto [从零开始DFS(0)] - DFS思想与框架/双重DFS HDOJ.1010 Tempter of the Bone [从零开始DFS(1)] -DFS四向搜索/奇偶剪枝 HDOJ(HDU).1015 Safecracker [从零开始DFS(2)] -DFS四向搜索变种 HDOJ(HDU).1016 Prime Ring Problem (DF…

因为是circle sequence,可以在序列最后+序列前n项(或前k项);利用前缀和思想,预处理出前i个数的和为sum[i],则i~j的和就为sum[j]-sum[i-1],对于每个j,取最小的sum[i-1],这就转成一道单调队列了,维护k个数的最小值. ---------------------------------------------------------------------------------- #include<cstdio> #include<deque&…

题目传送门 题意:求MCS(最大连续子序列和)及两个端点分析:第一种办法:dp[i] = max (dp[i-1] + a[i], a[i]) 可以不开数组,用一个sum表示前i个数字的MCS,其实是一样的...类似DP的做法有个名字叫联机算法. 第二种办法:一个前缀记录前i个数字的和,那么ans = sum - mn; mn表示前j个和且和最小 两种办法都是O (n) 1003就这么难?? 推荐学习资料:六种姿势拿下连续子序列最大和问题 最大子序列和问题 收获:MCS问题的两种o (n) 的算…

题目地址:http://acm.hdu.edu.cn/showproblem.php?pid=1024 Problem Description Now I think you have got an AC in Ignatius.L's "Max Sum" problem. To be a brave ACMer, we always challenge ourselves to more difficult problems. Now you are faced with a mor…