# Reverse Edges

Moderate
0/80
Average time to solve is 20m
Contributed by

## Problem statement

You are given a directed graph of ‘N’ nodes and ‘M’ edges. Also, you have two nodes ‘A’ and ‘B’. Your task is to make at least one valid path from ‘A’ to ‘B’ by doing the below operations a minimum number of times.

``````Choose two nodes ‘X’ and ‘Y’, such that there exists an edge from ‘X’ to ‘Y’.

Delete edge ‘X’ to ‘Y’.

``````

You need to print the minimum operations that you have done.

Detailed explanation ( Input/output format, Notes, Images )
Constraints:
``````1 <= T <= 5
1 <= N <= 3000
1 <= M <= min(3000, N*(N-1)/2)
0 <= X, Y, U, V <= N - 1

Time Limit : 1 sec
``````
##### Sample Input 1:
``````2
4 3
0 3
0 1
0 2
3 2
5 4
0 4
0 1
1 3
4 1
2 0
``````
##### Sample Output 1:
``````1
1
``````
##### Explanation For Sample Input 1:
``````Test Case 1 :
The given graph is shown below.
``````

``````Starting node = 0 and Ending node = 3.
We can reverse edge 3 -> 2 to make a valid path of 0 -> 2 -> 3.
So, the minimum number of operations required will be 1.

Test Case 2 :
The given graph is shown below.
``````

``````Starting node = 0 and Ending node = 4.
We can reverse edge 4 -> 1 to make a valid path of 0 -> 1 -> 4.
So the minimum number of operations required will be 1.
``````
##### Sample Input 2:
``````2
5 4
0 4
0 1
0 2
2 3
4 3
6 6
0 5
0 1
0 2
2 3
2 4
4 5
5 3
``````
##### Sample Output 2:
``````1
0
``````
Console