Count Edges Incident to a Node
EasyPractice library · +10 XPgraphsbfsdfs
Given an undirected graph with N nodes and M edges, and a target node T, count the total number of edges that are connected to node T. An edge is connected to node T if T is one of its endpoints.
Input
The first line contains three integers N, M, and T (1 <= T <= N <= 1000, 0 <= M <= 1000). The next M lines each contain two integers u and v, representing an edge between node u and node v (1 <= u, v <= N, u != v).
Output
Print a single integer: the number of edges incident to node T.
Constraints
1 <= T <= N <= 1000, 0 <= M <= 1000. Node labels are 1-indexed.
Time limit 1 s (native code; slower languages get more)Memory 256 MB14 hidden tests
Example 1
Input
5 4 3 1 2 2 3 3 4 4 5
Output
2
Node 3 is connected to edges (2,3) and (3,4), so the count is 2.
Example 2
Input
3 3 1 1 2 1 3 2 3
Output
2
Node 1 is connected to edges (1,2) and (1,3), so the count is 2.
Hints
# Read the input from stdin and print the answer.
import sys
def main():
data = sys.stdin.read().split()
# your code here
main()
Example 1 input
5 4 3 1 2 2 3 3 4 4 5
Example 2 input
3 3 1 1 2 1 3 2 3