max-flow

Author: ravish1729

max-flow/max-flow.cpp

@@ -0,0 +1,61 @@
+#include <iostream>
+#include <limits.h>
+using namespace std;
+#define n 6
+int g[6][6]={{0, 9, 9, 0, 0, 0},
+             {0, 0, 4, 8, 0, 0},
+             {0, 0, 0, 1, 3, 0},
+             {0, 0, 0, 0, 0, 10},
+             {0, 0, 0, 8, 0, 7},
+             {0, 0, 0, 0, 0, 0}};
+
+
+
+int bfs(int v,int *parent)
+{int visited[6]={0};
+ visited[v]=1;
+ int q[8];
+ int i,f=0,r=-1;
+ q[++r]=v;
+
+ while(f<=r)
+ {v=q[f++];
+  for(i=0;i<n;i++)
+  {if(visited[i]==0&&g[v][i]!=0)
+  {//cout<<i;
+   *(parent+i)=v;
+   q[++r]=i;
+   visited[i]=1;
+  }
+  }
+ }
+ return((visited[5]==1)?1:0);
+}
+
+
+int max_flow()
+{int i,j;
+ int parent[6]={-1};
+ int max_flow=0,flow=1000;
+
+ while(bfs(0,parent))
+ {for(i=5;i!=0;i=parent[i])
+  {j=parent[i];
+   flow=min(flow,g[j][i]);
+  }
+  
+  for(i=5;i!=0;i=parent[i])
+  {j=parent[i];
+   g[j][i]-=flow;
+   g[i][j]+=flow;
+  }
+  max_flow+=flow;
+ }
+
+ return(max_flow);
+}
+
+int main()
+{ cout << "The maximum possible flow is " << max_flow()<<endl;
+  return 0;
+}