Create edmonds_karp_algorithm.cpp

Please add my file with label hacktoberfest-2022

Author: ankitaga27

edmonds_karp_algorithm.cpp

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+#include<cstdio>
+#include<queue>
+#include<cstring>
+#include<vector>
+#include<iostream>
+using namespace std;
+int c[10][10];
+int flowPassed[10][10];
+vector<int> g[10];
+int parList[10];
+int currentPathC[10];
+int bfs(int sNode, int eNode)//breadth first search
+{
+   memset(parList, -1, sizeof(parList));
+   memset(currentPathC, 0, sizeof(currentPathC));
+   queue<int> q;//declare queue vector
+   q.push(sNode);
+   parList[sNode] = -1;//initialize parlist’s source node
+   currentPathC[sNode] = 999;//initialize currentpath’s source node
+   while(!q.empty())// if q is not empty
+   {
+      int currNode = q.front();
+      q.pop();
+      for(int i=0; i<g[currNode].size(); i++)
+      {
+         int to = g[currNode][i];
+         if(parList[to] == -1)
+         {
+            if(c[currNode][to] - flowPassed[currNode][to] > 0)
+            {
+               parList[to] = currNode;
+               currentPathC[to] = min(currentPathC[currNode],
+               c[currNode][to] - flowPassed[currNode][to]);
+               if(to == eNode)
+               {
+                  return currentPathC[eNode];
+               }
+               q.push(to);
+            }
+         }
+      }
+   }
+   return 0;
+}
+int edmondsKarp(int sNode, int eNode)
+{
+   int maxFlow = 0;
+   while(true)
+   {
+      int flow = bfs(sNode, eNode);
+      if (flow == 0)
+      {
+         break;
+      }
+      maxFlow += flow;
+      int currNode = eNode;
+      while(currNode != sNode)
+      {
+         int prevNode = parList[currNode];
+         flowPassed[prevNode][currNode] += flow;
+         flowPassed[currNode][prevNode] -= flow;
+         currNode = prevNode;
+      }
+   }
+return maxFlow;
+}
+int main()
+{
+   int nodCount, edCount;
+   cout<<"enter the number of nodes and edges\n";
+   cin>>nodCount>>edCount;
+   int source, sink;
+   cout<<"enter the source and sink\n";
+   cin>>source>>sink;
+   for(int ed = 0; ed < edCount; ed++)
+   {
+      cout<<"enter the start and end vertex along with capacity\n";
+      int from, to, cap;
+      cin>>from>>to>>cap;
+      c[from][to] = cap;
+      g[from].push_back(to);
+      g[to].push_back(from);
+   }
+   int maxFlow = edmondsKarp(source, sink);
+   cout<<endl<<endl<<"Max Flow is:"<<maxFlow<<endl;
+}