Initial data commit

Task/Resistor-mesh/C-sharp/resistor-mesh.cs

@@ -0,0 +1,108 @@
+using System;
+using System.Collections.Generic;
+
+namespace ResistorMesh {
+    class Node {
+        public Node(double v, int fixed_) {
+            V = v;
+            Fixed = fixed_;
+        }
+
+        public double V { get; set; }
+        public int Fixed { get; set; }
+    }
+
+    class Program {
+        static void SetBoundary(List<List<Node>> m) {
+            m[1][1].V = 1.0;
+            m[1][1].Fixed = 1;
+
+            m[6][7].V = -1.0;
+            m[6][7].Fixed = -1;
+        }
+
+        static double CalcuateDifference(List<List<Node>> m, List<List<Node>> d, int w, int h) {
+            double total = 0.0;
+            for (int i = 0; i < h; i++) {
+                for (int j = 0; j < w; j++) {
+                    double v = 0.0;
+                    int n = 0;
+                    if (i > 0) {
+                        v += m[i - 1][j].V;
+                        n++;
+                    }
+                    if (j > 0) {
+                        v += m[i][j - 1].V;
+                        n++;
+                    }
+                    if (i + 1 < h) {
+                        v += m[i + 1][j].V;
+                        n++;
+                    }
+                    if (j + 1 < w) {
+                        v += m[i][j + 1].V;
+                        n++;
+                    }
+                    v = m[i][j].V - v / n;
+                    d[i][j].V = v;
+                    if (m[i][j].Fixed == 0) {
+                        total += v * v;
+                    }
+                }
+            }
+            return total;
+        }
+
+        static double Iter(List<List<Node>> m, int w, int h) {
+            List<List<Node>> d = new List<List<Node>>(h);
+            for (int i = 0; i < h; i++) {
+                List<Node> t = new List<Node>(w);
+                for (int j = 0; j < w; j++) {
+                    t.Add(new Node(0.0, 0));
+                }
+                d.Add(t);
+            }
+
+            double[] curr = new double[3];
+            double diff = 1e10;
+
+            while (diff > 1e-24) {
+                SetBoundary(m);
+                diff = CalcuateDifference(m, d, w, h);
+                for (int i = 0; i < h; i++) {
+                    for (int j = 0; j < w; j++) {
+                        m[i][j].V -= d[i][j].V;
+                    }
+                }
+            }
+
+            for (int i = 0; i < h; i++) {
+                for (int j = 0; j < w; j++) {
+                    int k = 0;
+                    if (i != 0) k++;
+                    if (j != 0) k++;
+                    if (i < h - 1) k++;
+                    if (j < w - 1) k++;
+                    curr[m[i][j].Fixed + 1] += d[i][j].V * k;
+                }
+            }
+
+            return (curr[2] - curr[0]) / 2.0;
+        }
+
+        const int S = 10;
+        static void Main(string[] args) {
+            List<List<Node>> mesh = new List<List<Node>>(S);
+            for (int i = 0; i < S; i++) {
+                List<Node> t = new List<Node>(S);
+                for (int j = 0; j < S; j++) {
+                    t.Add(new Node(0.0, 0));
+                }
+                mesh.Add(t);
+            }
+
+            double r = 2.0 / Iter(mesh, S, S);
+            Console.WriteLine("R = {0:F15}", r);
+        }
+    }
+}