New update is available. Click here to update.

Solve problems & track your progress

Checkout your overall progress in every topic here

Become

Sensei

in DSA topics

Open the topic and solve more problems associated with it to improve your skills

Check out the skill meter for every topic

See how many problems you are left with to solve for cracking any stage. Score more than zero to get your progress counted.

Problem

Submissions

Check If Path Exists

Contributed by

Waris

Easy

0/40

Avg time to solve 10 mins

Success Rate 90 %

6 upvotes

Problem Statement

You are given a directed and unweighted graph of 'V' vertices and 'E' edges. All edges are given in a 2-dimensional array ‘Edges’ in which ‘Edges[i][0]’ and ‘Edges[i][1]’ contain an edge. Your task is to check if there exists a path from the vertex 'source' to 'destination'.

For Example:

Consider the number of vertices is 4 and number of edges is 3, and the array of edges is:
[ [0, 1]
  [1, 2] 
  [2, 3] ]
there exists one path between 0 and 2, which is 0 -> 1 -> 2. Hence, the answer is 'true'.

Detailed explanation ( Input/output format, Notes, Constraints, Images )

Input format :

The first line of input contains an integer ‘T’, the number of test cases.

The first line of each test case contains two space-separated integers, ‘V’, and ‘E’, which denote the number of vertices and edges in the graph.

The next 'E' lines will denote the edges of the graph where every edge is defined by two space-separated integers 'Edges[i][0]’ and 'Edges[i][1]', which signifies an edge from vertex 'Edges[i][0]’ to vertex 'Edges[i][1]’.

The last line of each test case contains two integers, ‘source’ and ‘destination’.

Output Format :

For each test case, print 'true' if there exists a path from vertex 'source' to 'destination'. Otherwise, print 'false'.

Print the output of each test case in a separate line.

Note:

You do not need to print anything, it has already been taken care of. Just implement the given function.

Constraints:

1 <= T <= 5
1 <= V, E <= 10 ^ 5
0 <= Edges[i][0], Edges[i][1] < V
0 <= source, destination < V

Time Limit: 1 sec

Sample Input 1:

Sample Output 1:

true 
false

Explanation:

In test case 1:
In this, there are 3 vertices and 3 edges, and there is a path between 0 and 2 which is 0 -> 1 -> 2. Hence, the answer is true.

In test case 2:
In this, there are 4 vertices and 2 edges, and there is no path between 0 and 2. Hence, the answer is false.

Sample Input 2:

Sample Output 2:

false

Explanation:

There are 4 vertices and 5 edges, and there is no path between 3 and 1, so our answer is false.

Auto

Console