Out-degree of a vertex

Challenge

Graphs here use an adjacency matrix: adj[i*n+j]==1 means a directed edge i→j.

int out_degree(const int *adj,int n,int v);

Return the out-degree of vertex v (number of edges leaving it).

Input format

adj is n×n row-major 0/1; 0<=v<n.

Output format

Out-degree of v.

Constraints

No self-loops in tests.

Starter code

#include <stddef.h>
/* Adjacency matrix adj (n x n, row-major): adj[i*n+j]=1 means an edge i->j. Return the out-degree of v (edges leaving v). */
int out_degree(const int *adj,int n,int v){ (void)adj;(void)n;(void)v; return 0; }

Common mistakes

Indexing the column instead of the row; that gives in-degree.

Edge cases to handle

Isolated vertex → 0; row of all 1s → n.

Background lessons

• Graph representation