Vishwajith S.S.
205002127
Ex 11
1) Design, Develop and Implement a Program in C for the following operations on Graph(G) of Cities.
(a) Create a Graph of N cities using Adjacency Matrix.
(b) Print all the nodes reachable from a given starting node in a digraph using DFS and BFS method.
(c) Find the complexity of the Graph.
Code:
#include <iostream>
using namespace std;
int adjacency[50][50], n, visited[50];
int q[20], front = -1, rear = -1;
int s[20], top = -1, count = 0;
void bfs(int v){
int i, cur;
visited[v] = 1;
q[++rear] = v;
while (front != rear){
cur = q[++front];
for (i = 1; i <= n; i++){
if ((adjacency[cur][i] == 1) && (visited[i] == 0)){
q[++rear] = i;
visited[i] = 1;
cout << i << " ";
}
}
}
}
void dfs(int v){
int i;
visited[v] = 1;
s[++top] = v;
for (i = 1; i <= n; i++){
if (adjacency[v][i] == 1 && visited[i] == 0){
cout << i << " ";
dfs(i);
}
}
}
int main(){
int ch, start, i, j;
cout << "\nEnter the number of vertices in graph: ";
cin >> n;
cout << "\nEnter the adjacency matrix:\n";
for (i = 1; i <= n; i++){
for (j = 1; j <= n; j++)
cin >> adjacency[i][j];
}
for (i = 1; i <= n; i++)
visited[i] = 0;
cout << "\nEnter the starting vertex: ";
cin >> start;
cout << "\n1. BFS search";
cout << "\n2. DFS search";
cout << "\n3:Exit";
cout << "\nEnter your choice: ";
cin >> ch;
switch (ch){
case 1:
cout << "\nNodes reachable from starting vertex " << start << "
are: " << start;
bfs(start);
for (i = 1; i <= n; i++){
if (visited[i] == 0)
cout << "\nThe vertex that is not reachable is " << i;
}
break;
case 2:
cout << "\nNodes reachable from starting vertex " << start << "
are:\n";
dfs(start);
break;
}
}
Output:
2) Show the ordering of vertices produced by the topological sort algorithm.
Code:
#include <iostream>
#include <list>
#include <stack>
using namespace std;
class Graph{
int V;
list<int> *adj;
void topologicalSortUtil(int v, bool visited[], stack<int> &Stack);
public:
Graph(int V);
void addEdge(int v, int w);
void topologicalSort();
};
Graph::Graph(int V){
this->V = V;
adj = new list<int>[V];
}
void Graph::addEdge(int v, int w){
adj[v].push_back(w);
}
void Graph::topologicalSortUtil(int v, bool visited[], stack<int> &Stack){
visited[v] = true;
list<int>::iterator i;
for (i = adj[v].begin(); i != adj[v].end(); ++i)
if (!visited[*i])
topologicalSortUtil(*i, visited, Stack);
Stack.push(v);
}
void Graph::topologicalSort(){
stack<int> Stack;
bool *visited = new bool[V];
for (int i = 0; i < V; i++)
visited[i] = false;
for (int i = 0; i < V; i++)
if (visited[i] == false)
topologicalSortUtil(i, visited, Stack);
while (Stack.empty() == false){
cout << Stack.top() << " ";
Stack.pop();
}
}
int main(){
Graph g(6);
g.addEdge(0, 1);
g.addEdge(0, 3);
g.addEdge(1, 2);
g.addEdge(1, 3);
g.addEdge(2, 3);
g.addEdge(2, 4);
g.addEdge(3, 4);
g.addEdge(2, 5);
g.addEdge(3, 5);
g.addEdge(4, 5);
cout << "Topological Sort of the given graph n is:
g.topologicalSort();
return 0;
}
";