Hi all,

I am currently stuck on a problem that can be solved by finding the minimum cost of the maximum flow in a graph with lower and upper bounds on edge capacities.

My problem combines aspects of minimum-cost flow and maximum flow with node demands. I have also come across the "Minimum Cost b-Flow" problem, which is similar, but it does not maximize the total flow.

Does anyone have any ideas for solving this problem? Thanks in advance.

Hello everyone,

I have some trouble with a problem and I hope someone may help me to solve it:

Given a graph N vertices and M edges (N <= 50, M <= N * (N — 1) / 2). Each edge has a weight w (w <= 1e4). And the task is to find if there is a path with the total weight exactly equals to S (S <= 1e18).

Thanks in advance!

Hello, can anyone help me with this problem:

Given N rooms (N <= 100), at first, each room was painted by one color (0, 1 or 2). There are N robots, each robot has a set of rooms that we can use to paint all elements in. For an room after painting, its color changes from 0 to 1, 1 to 2 and 2 to 0.

Calculate the minimum times need to use robots to make all the rooms have color 0. (A robot can be used multiple times).

Thanks so much!

Hello everyone, can you help me with this problem:

Given a tree has N vertice (N <= 3*10^5) and a number K (K <= n — 1). Each edge in this tree has a weight W (- 10^6 <= W <= 10^6).

You should choose exactly K edges that the sum of their weight is maximum and mustn't choose 2 edges that connect with the same vertex.

I think with N and K small, this problem can be solved using dp.

Thanks!

Hello,

Given a grid N x M (N x M <= 100). Your task is to count how many Hamilton cycles in this graph. Are there any algorithms to solve this?

Thanks!

Hello everyone,

Is there an algorithm to build Suffix Array in complexity O(n)?

Thanks in advance!