CodeForces 75D Big Maximum Sum

最新推荐文章于 2024-10-01 18:52:56 发布

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最新推荐文章于 2024-10-01 18:52:56 发布 · 582 阅读

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#动态规划 #codeforces

本篇博客介绍了如何解决一个基于给定的小数组构建大数组并求解最大子序列和的问题。博客内容包括题意解析、暴力解法的局限性以及采用动态规划的解决方案，通过维护从左端点和右端点开始的最大区间和来求解大数组的最大和。

D. Big Maximum Sum

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Ahmed and Mostafa used to compete together in many programming contests for several years. Their coach Fegla asked them to solve one challenging problem, of course Ahmed was able to solve it but Mostafa couldn't.

This problem is similar to a standard problem but it has a different format and constraints.

In the standard problem you are given an array of integers, and you have to find one or more consecutive elements in this array where their sum is the maximum possible sum.

But in this problem you are given n small arrays, and you will create one big array from the concatenation of one or more instances of the small arrays (each small array could occur more than once). The big array will be given as an array of indexes (1-based) of the small arrays, and the concatenation should be done in the same order as in this array. Then you should apply the standard problem mentioned above on the resulting big array.

For example let's suppose that the small arrays are {1, 6, -2}, {3, 3} and {-5, 1}. And the indexes in the big array are {2, 3, 1, 3}. So the actual values in the big array