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  1. using static IO;
  2. public class IO {
  3. public static IO Cin = new();
  4. public static StreamReader reader = new(Console.OpenStandardInput());
  5. public static StreamWriter writer = new(Console.OpenStandardOutput());
  6. public static implicit operator string(IO _) => reader.ReadLine();
  7. public static implicit operator char[](IO _) => reader.ReadLine().ToArray();
  8. public static implicit operator int(IO _) => int.Parse(reader.ReadLine());
  9. public static implicit operator double(IO _) => double.Parse(reader.ReadLine());
  10. public static implicit operator string[](IO _) => reader.ReadLine().Split();
  11. public static implicit operator int[](IO _) => Array.ConvertAll(reader.ReadLine().Split(), int.Parse);
  12. public void Deconstruct(out int a, out int b) { int[] r = Cin; (a, b) = (r[0], r[1]); }
  13. public void Deconstruct(out int a, out int b, out int c) { int[] r = Cin; (a, b, c) = (r[0], r[1], r[2]); }
  14. public static IEnumerable<int> MakeRange(int start, int count) => Enumerable.Range(start, count);
  15. public static T[] MakeArray<T>(int count) where T : new() => MakeRange(0, count).Select(_ => new T()).ToArray();
  16. public static object? Cout { set { writer.Write(value); } }
  17. public static object? Coutln { set { writer.WriteLine(value); } }
  18. public static void Main() { Program.Coding(); writer.Flush(); }
  19. }
  20. class Program {
  21.     record struct Point(ushort X, ushort Y) {
  22.         public readonly int GetIndex(int n) => Y * n + X;
  23.     }
  24.     public static void Coding() {
  25.         checked {
  26.             (int n, int blind) = Cin;
  27.  
  28.             int source = n * n;
  29.             int limiter = source + 1;
  30.             int sink = limiter + 1;
  31.  
  32.             int[][] eggs = MakeRange(0, n).Select(_ => (int[])Cin).ToArray();
  33.             PriorityQueue<(Point a, Point b), int> candidate = new();
  34.  
  35.             for (ushort y = 0; y < n; y++) {
  36.                 for (ushort x = 1; x < n; x++) {
  37.                     candidate.Enqueue((new((ushort)(x - 1), y), new(x, y)), eggs[y][x - 1] + eggs[y][x]);
  38.                 }
  39.             }
  40.             for (ushort x = 0; x < n; x++) {
  41.                 for (ushort y = 1; y < n; y++) {
  42.                     candidate.Enqueue((new(x, (ushort)(y - 1)), new(x, y)), eggs[y - 1][x] + eggs[y][x]);
  43.                 }
  44.                 candidate.Dequeue();
  45.             }
  46.  
  47.             FlowGraph graph = new(sink + 1);
  48.             for (int y = 0; y < n; y++) {
  49.                 for (int x = 0; x < n; x++) {
  50.                     int me = y * n + x;
  51.                     if ((x + y) % 2 is 0) {
  52.                         graph.AddLine(limiter, me, 1, -eggs[y][x]);
  53.                     }
  54.                     else {
  55.                         graph.AddLine(me, sink, 1, -eggs[y][x]);
  56.                     }
  57.                 }
  58.             }
  59.             while (candidate.Count > 0) {
  60.                 var (a, b) = candidate.Dequeue();
  61.                 if ((a.X + a.Y) % 2 is not 0) (a, b) = (b, a);
  62.                 graph.AddLine(a.GetIndex(n), b.GetIndex(n), 1, 0);
  63.             }
  64.  
  65.             graph.AddLine(source, limiter, blind, 0);
  66.             _ = graph.GetMaxFlow(source, sink, out int cost);
  67.             Cout = eggs.Sum(arr => arr.Sum()) + cost;
  68.         }
  69.     }
  70. }
  71. class FlowLine {
  72.     public int Start { get; }
  73.     public int End { get; }
  74.     public int Capacity { get; }
  75.     public int Flow { get; set; } = 0;
  76.     public FlowLine Reverse { get; }
  77.     public int Remaining => Capacity - Flow;
  78.     public int Cost { get; }
  79.     public FlowLine(int start, int end, int capacity, int cost, FlowLine? reverse = null) {
  80.         this.Start = start;
  81.         this.End = end;
  82.         this.Capacity = capacity;
  83.         this.Cost = cost;
  84.         this.Reverse = reverse ?? new(end, start, 0, -cost, this);
  85.     }
  86. }
  87. class FlowGraph {
  88.     public FlowGraph(int size) {
  89.         graph = MakeArray<List<FlowLine>>(Count = size);
  90.     }
  91.     public void AddLine(int start, int end, int capacity, int cost) {
  92.         FlowLine line = new(start, end, capacity, cost);
  93.         graph[start].Add(line);
  94.         graph[end].Add(line.Reverse);
  95.     }
  96.     public int GetMaxFlow(int source, int sink, out int cost) {
  97.         int totalFlow = 0;
  98.         for (cost = 0; true;) {
  99.             FlowLine?[] path = new FlowLine?[Count];
  100.             int[] dist = Enumerable.Repeat(int.MaxValue, Count).ToArray();
  101.             bool[] inQueue = new bool[Count];
  102.             Queue<int> queue = new();
  103.             dist[source] = 0;
  104.             inQueue[source] = true;
  105.             queue.Enqueue(source);
  106.             while (queue.Count > 0) {
  107.                 int node = queue.Dequeue();
  108.                 inQueue[node] = false;
  109.                 foreach (var line in graph[node]) {
  110.                     int nextdist = dist[node] + line.Cost;
  111.                     if (line.Remaining > 0 && dist[line.End] > nextdist) {
  112.                         dist[line.End] = nextdist;
  113.                         path[line.End] = line;
  114.                         if (inQueue[line.End] is false) {
  115.                             inQueue[line.End] = true;
  116.                             queue.Enqueue(line.End);
  117.                         }
  118.                     }
  119.                 }
  120.             }
  121.             if (path[sink] is not FlowLine sinkLine) break;
  122.             int flow = int.MaxValue;
  123.             for (FlowLine? line = sinkLine; line is not null; line = path[line.Start]) {
  124.                 flow = Math.Min(flow, line.Remaining);
  125.             }
  126.             for (FlowLine? line = sinkLine; line is not null; line = path[line.Start]) {
  127.                 line.Flow += flow;
  128.                 line.Reverse.Flow -= flow;
  129.                 cost += flow * line.Cost;
  130.             }
  131.             totalFlow += flow;
  132.         }
  133.         return totalFlow;
  134.     }
  135.     public int Count { get; }
  136.     private readonly List<FlowLine>[] graph;
  137. }
Success #stdin #stdout 0.06s 33740KB
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https://ideone.com/pQSZdu
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language:
C# (NET 6.0)
created:
10 days ago
visibility:
public

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