Try - Sqashing Commits

Boyer_Moore_Algorithm/Boyer_Moore.cs

@@ -0,0 +1,110 @@
+// C# Program for Boyer Moore String Matching Algorithm 
+
+using System;
+
+public class Algorithm
+{ 
+    static int CHARACTERS = 256; 
+
+    // Getting maximum of two integers 
+    static int max (int a, int b) { return (a > b)? a: b; } 
+
+    // Bad Character Pre-Processing Function
+    static void badChar( char []str, int size,int []badCharacter) 
+    { 
+        int i; 
+
+        // Initializing all occurences to -1 
+        for (i = 0; i < CHARACTERS; i++)
+            badCharacter[i] = -1; 
+
+        // Filling the Actual Value
+        for (i = 0; i < size; i++) 
+            badCharacter[(int) str[i]] = i;
+    } 
+
+    // Pattern Searching Function
+    static void search( char []txt, char []pat) 
+    {
+        int m = pat.Length; 
+        int n = txt.Length;
+
+        int []Character = new int[CHARACTERS];
+        badChar(pat, m, Character); 
+
+        /* 
+            s is used to keep track of 
+            pattern shifting with respect to text
+        */
+
+        int s = 0; 
+
+        while(s <= (n - m))
+        {
+            int j = m - 1; 
+
+            while(j >= 0 && pat[j] == txt[s+j])
+                j--; 
+
+            /* 
+                If the pattern is present at current 
+                shift, then index j will become -1 after 
+                the above loop 
+            */
+
+            if (j < 0) 
+            { 
+                Console.WriteLine("Pattern occurs at index: " + s); 
+                s += (s+m < n)? m-Character[txt[s+m]] : 1; 
+            } 
+
+            else 
+                s += max(1, j - Character[txt[s+j]]); 
+
+        } 
+    } 
+
+    public static void Main() 
+    { 
+        Console.WriteLine("Enter The String Value: ");
+        String valueEntered = Console.ReadLine(); 
+        Console.WriteLine("Enter The Pattern To Search: ");
+        String pattern = Console.ReadLine();
+        Console.WriteLine(); 
+
+        char []txt = valueEntered.ToCharArray(); 
+        char []pat = pattern.ToCharArray(); 
+        search(txt, pat); 
+    } 
+} 
+
+/**
+
+Enter The String Value: 
+ABAAABCD
+Enter The Pattern To Search: 
+ABC
+
+Pattern occurs at index: 4
+
+--------------------------------------------------
+
+Enter The String Value: 
+AABAACAADAABAABA
+Enter The Pattern To Search: 
+AABA
+
+Pattern occurs at index: 0
+Pattern occurs at index: 9
+Pattern occurs at index: 12
+
+--------------------------------------------------
+
+Enter The String Value: 
+THIS IS A TEST TEXT
+Enter The Pattern To Search: 
+TEST
+
+Pattern occurs at index: 10
+
+*/

Johnson_Algorithm/Johnson_Algorithm.dart

@@ -0,0 +1,180 @@
+/*
+Johnson’s algorithm for All-pairs shortest paths
+
+Given a weighted Directed Graph where the weights may be negative,
+find the shortest path between every pair of vertices in the Graph using
+Johnson’s Algorithm.
+ */
+
+int MAX_INT = 9223372036854775807;
+
+int minDistance(distance, visited)
+{
+    var minimum  = MAX_INT;
+    var minVertex = 0;
+
+    var v = distance.length;
+
+    for(var vertex = 0; vertex < v; vertex++)
+    {
+        if( (minimum > distance[vertex]) && (visited[vertex] == false) )
+        {
+            minimum = distance[vertex];
+            minVertex = vertex;
+        }
+    }
+    return minVertex;
+}
+
+void Dijkstra(graph, modified, src)
+{
+    var num_vertices = graph.length;
+    var distance = new List(num_vertices);
+
+    var visited = new List(num_vertices);
+
+    for (var i = 0; i < num_vertices; i++)
+    {
+        distance[i] = MAX_INT;
+        visited[i] = false;
+    }
+
+    distance[src] = 0;
+
+    for(var count = 0; count < num_vertices; count++)
+    {
+        var curVertex = minDistance(distance, visited);
+        visited[curVertex] = true;
+        for(var vertex = 0; vertex < num_vertices; vertex++)
+        {
+            if ((visited[vertex] == false) && (distance[vertex] > (distance[curVertex] +
+            modified[curVertex][vertex])) && (graph[curVertex][vertex] != 0))
+            {
+               distance[vertex] = (distance[curVertex] + modified[curVertex][vertex]);
+            }
+        }
+    }
+
+    for(var vertex = 0; vertex < num_vertices; vertex++)
+    {
+        print('Vertex   ${vertex} :  ${distance[vertex]}');
+    }
+}
+
+List BellmanFord(edges, graph, num_vertices)
+{
+    var distance = new List(num_vertices+1);
+
+    for(var i = 0; i <= num_vertices; i++)
+    {
+        distance[i]=MAX_INT;
+    }
+
+    distance[num_vertices] = 0;
+
+    for(var i = 0; i < num_vertices; i++)
+    {
+        edges.add([num_vertices, i, 0]);
+    }
+
+    for(var i = 0; i < num_vertices; i++)
+    {
+        for(var j in edges)
+        {
+
+            if((distance[j[0]] != MAX_INT) && (distance[j[0]] + j[2] < distance[j[1]]) )
+            {
+                distance[j[1]] = distance[j[0]] + j[2];
+            }
+        }
+    }
+
+    return distance;
+}
+
+
+void JohnsonAlgorithm(graph)
+{
+    var edges = new List();
+
+    for(var i = 0; i < graph.length ; i++)
+    {
+        for(var j = 0; j < graph[i].length; j++)
+        {
+          if(graph[i][j] != 0)
+          {
+              edges.add([i, j, graph[i][j]]);
+          }
+        }
+    }
+
+    var modifiedwei = BellmanFord(edges, graph, graph.length);
+
+    var modified = [[0,0,0,0],
+                        [0,0,0,0],
+                        [0,0,0,0],
+                        [0,0,0,0]];
+
+    for(var i = 0; i < graph.length; i++)
+    {
+        for(var j = 0; j < graph[i].length; j++)
+        {
+            if(graph[i][j] != 0)
+            {
+                modified[i][j] = (graph[i][j] +
+                modifiedwei[i] - modifiedwei[j]);
+            }
+        }
+    }
+
+    print ('Modified Graph: ${modified}');
+
+    for(var src = 0; src < graph.length; src++)
+    {
+        print ('\nShortest Distance with vertex ${src} as the source:\n');
+        Dijkstra(graph, modified, src);
+    }
+}
+
+void main() {
+
+    var graph = [[0, -8, 2, 4],
+                  [0, 0, 2, 6],
+                  [0, 0, 0, 2],
+                  [0, 0, 0, 0]];
+
+    JohnsonAlgorithm(graph);
+}
+
+/*
+Modified Graph: [[0, 0, 8, 8], [0, 0, 0, 2], [0, 0, 0, 0], [0, 0, 0, 0]]
+
+Shortest Distance with vertex 0 as the source:
+
+Vertex   0 :  0
+Vertex   1 :  0
+Vertex   2 :  0
+Vertex   3 :  0
+
+Shortest Distance with vertex 1 as the source:
+
+Vertex   0 :  9223372036854775807
+Vertex   1 :  0
+Vertex   2 :  0
+Vertex   3 :  0
+
+Shortest Distance with vertex 2 as the source:
+
+Vertex   0 :  9223372036854775807
+Vertex   1 :  9223372036854775807
+Vertex   2 :  0
+Vertex   3 :  0
+
+Shortest Distance with vertex 3 as the source:
+
+Vertex   0 :  9223372036854775807
+Vertex   1 :  9223372036854775807
+Vertex   2 :  -9223372036854775801
+Vertex   3 :  0
+
+ */