[24 questions about network stream] ---- problem solving (partial, continuous update...), ---- Problem Solving
Combined with pilots
With PILOT: http://cogs.yeefan.us/cogs/problem/problem.php? Pid = 14
Problem: create a virtual source sink and
Code: http://cogs.yeefan.us/cogs/submit/code.php? Id = 148410
Numerical Trapezoid
Digit trapezoid: http://cogs.yeefan.us/cogs/problem/problem.php? Pid = 1, 738
Question:
Rule (1)
Abstract each position in the trapezoid into two points (I. a) and (I. B), and create an additional S sink T.
1. For each vertex I from (I. a) to (I. B), the capacity of a connection is 1, and the cost is the directed edge of the vertex I weight.
2. From S to the top layer of the trapezoid, each (I. a) connects to a directed edge with a capacity of 1 and a cost of 0.
3. From the bottom layer of the trapezoid, each (I. B) connects to T with a directed edge with a capacity of 1 and a cost of 0.
4. For each vertex I and the following two vertex j, a directed edge is connected from (I. B) to (j. a) with a capacity of 1 and a cost of 0.
Find the maximum flow of the maximum fee. The flow value is the result.
Rules (2)
Consider each position in the trapezoid as a vertex I, and create an additional S sink T.
1. From S to the top layer of the trapezoid, each I connects a directed edge with a capacity of 1 and a cost of 0.
2. From the bottom layer of the trapezoid, each I-to-T connects a directed edge with an infinite capacity and a cost of 0.
3. For each vertex I and the following two vertex j, the capacity of a link from I to j is 1, and the cost is the directed edge of the vertex I weight.
Find the maximum flow of the maximum fee. The flow value is the result.
Rules (3)
Consider each position in the trapezoid as a vertex I, and create an additional S sink T.
1. From S to the top layer of the trapezoid, each I connects a directed edge with a capacity of 1 and a cost of 0.
2. From the bottom layer of the trapezoid, each I-to-T connects a directed edge with an infinite capacity and a cost of 0.
3. For each vertex I and the following two vertex j, the capacity of a link from I to j is infinite, and the cost is the directed edge of the vertex I weight value.
Find the maximum flow of the maximum fee. The flow value is the result.
In fact, both the second and third are well-handled, that is, the first is a little troublesome. For this question, we have established n rows which are relatively easy to write.
Code: http://cogs.yeefan.us/cogs/submit/code.php? Id = 157717
Load Balancing
Load Balancing: http://cogs.yeefan.us/cogs/problem/problem.php? Pid = 1, 741
Question:
First, obtain the average inventory quantity of all warehouses, and set the surplus volume of the I-th warehouse to A [I], A [I] = the original inventory volume of the I-th warehouse-average inventory volume. Create a bipartite graph and abstract each warehouse into two nodes Xi and Yi. Add additional source s t.
1. If A [I]> 0, A directed edge with A capacity of A [I] From S to Xi is charged.
2. If A [I] <0, A directed edge with A capacity of-A [I] is connected from Yi to T, and the cost is 0.
3. Each Xi is directed to two adjacent vertex j. A directed edge with a capacity of 1 is connected from Xi to Xj, and a directed edge with a capacity of 1 is connected from Xi to Yj, the cost is 1 directed edge.
The minimum fee is the maximum flow, and the minimum charge flow value is the minimum amount of transportation.
Code: http://cogs.yeefan.us/cogs/submit/code.php? Id = 157626