From 57bff86903996d92827ff381c406748ebeb83ab6 Mon Sep 17 00:00:00 2001
From: Shreya <76070994+Shreya587@users.noreply.github.com>
Date: Sun, 23 Oct 2022 21:58:43 +0530
Subject: [PATCH] Created Shortest Path Using BFS

---
 Shortest_path_BFS.cpp | 59 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 Shortest_path_BFS.cpp

diff --git a/Shortest_path_BFS.cpp b/Shortest_path_BFS.cpp
new file mode 100644
index 0000000..5683b41
--- /dev/null
+++ b/Shortest_path_BFS.cpp
@@ -0,0 +1,59 @@
+//Shortest path in undirected graph using BFS.
+
+#include<bits/stdc++.h>
+using namespace std;
+#define ll long long
+
+vector<ll> adj[10005];
+ll dis[10005],vis[10005];
+
+void bfs(ll src){
+    
+    queue<ll> q;
+    vis[src]=1;
+    dis[src]=0;
+    q.push(src);
+    
+    while(!q.empty()){
+
+        int node = q.front();
+        q.pop();
+        
+        for(auto it : adj[node]){       //traversing in the adjacency list.
+            if(vis[it]==0){
+                dis[it]=dis[node]+1;
+                q.push(it);
+                vis[it]=1;
+            }
+        }
+    }
+}
+
+int main(){
+    ios_base::sync_with_stdio(false);
+    cin.tie(0);
+    cout.tie(0);
+
+    ll t;
+    cin>>t;
+    
+    while(t--){
+
+    ll n,m;   //no. of nodes & vertices.
+    cin>>n>>m;
+    
+    for(ll i=0;i<=n;i++) adj[i].clear() , vis[i]=0;
+
+    while(m--){
+      ll a,b;
+        cin>>a>>b;  adj[a].push_back(b);  adj[b].push_back(a);
+    }
+    
+    bfs(1);       //calling the above BFS function.
+  
+    for(ll i = 1; i <= n; i++)    //printing path from source to ith node.
+    cout<<dis[i]<<" ";
+    
+    cout<<endl;
+    }
+}
\ No newline at end of file