# Find indegree and outdegree of a directed graph in c

C program for Find indegree and outdegree of a directed graph. Here problem description and other solutions.

``````// C program for
// Show degree of vertex in directed graph
#include <stdio.h>
#include <stdlib.h>

struct AjlistNode
{
int id;
// Vertices id
struct AjlistNode *next;
};
struct Vertices
{
int data;
struct AjlistNode *next;
struct AjlistNode *last;
};
struct Graph
{
int size;
struct Vertices *node;
};
//set node key value
void setData(struct Graph *g)
{
if (g->node != NULL)
{
int index = 0;
for (int index = 0; index < g->size; index++)
{
// Set vertic node data
g->node[index].data = index;
// Set NULL Value
g->node[index].next = NULL;
g->node[index].next = NULL;
}
}
else
{
printf("Vertic Node is Empty");
}
}
// Return new graph
struct Graph *newGraph(int size)
{
if (size < 1)
{
printf("\n Invalid graph size ");
exit(0);
}
struct Graph *g = (struct Graph *)
malloc(sizeof(struct Graph));
g->size = size;
g->node = (struct Vertices *)
malloc(sizeof(struct Vertices) *size);
setData(g);
return g;
}
// Connect two nodes
void connect(struct Graph *g, int start, int last)
{
struct AjlistNode *edge = (struct AjlistNode *)
malloc(sizeof(struct AjlistNode));
if (edge != NULL)
{
edge->id = last;
edge->next = NULL;
if (g->node[start].next == NULL)
{
g->node[start].next = edge;
}
else
{
// Add edge at the end
g->node[start].last->next = edge;
}
// Get last edge
g->node[start].last = edge;
}
else
{
printf("\n Memory overflow to create edge");
}
}
// Add Edge from Two given Nodes
void addEdge(struct Graph *g, int start, int last)
{
if (start < g->size && last < g->size)
{
connect(g, start, last);
}
else
{
//not valid Vertices
printf("Invalid Node Vertices %d  %d", start, last);
}
}
// Display Adjacency list of vertex
void printGraph(struct Graph *g)
{
if (g != NULL)
{
struct AjlistNode *temp = NULL;
for (int index = 0; index < g->size; index++)
{
printf("\n Adjacency list of vertex %d  :", index);
temp = g->node[index].next;
// Display edge
while (temp != NULL)
{
printf("  %d", g->node[temp->id].data);
temp = temp->next;
}
}
}
else
{
printf("Empty Graph");
}
}
// Find indegree and outdegree of
// each nodes of a given graph
void findDegree(struct Graph *g, int indegree[], int outdegree[])
{
struct AjlistNode *temp = NULL;
int length = 0;
for (int i = 0; i < g->size; ++i)
{
temp = g->node[i].next;
length = 0;
while (temp != NULL)
{
// Update indegree
indegree[temp->id]++;
temp = temp->next;
length++;
}
// Set outdegree value
outdegree[i] = length;
}
}
void showDegree(struct Graph *g)
{
if (g->node != NULL && g->size > 0)
{
int indegree[g->size];
int outdegree[g->size];
// Set zero degree
for (int i = 0; i < g->size; i++)
{
indegree[i] = 0;
outdegree[i] = 0;
}
// Find degree
findDegree(g, indegree, outdegree);
printf("\n\n");
// Display result
for (int i = 0; i < g->size; ++i)
{
printf("Node [%d] indegree [%d] outdegree [%d]\n",
i, indegree[i], outdegree[i]);
}
}
else
{
printf("Empty Graph");
}
}
int main()
{
// 6 implies the number of nodes in graph
struct Graph *g = newGraph(6);
// Connected two node with Edges
printGraph(g);
// Test
showDegree(g);
return 0;
}``````

Output

`````` Adjacency list of vertex 0  :  1  2  5
Adjacency list of vertex 1  :
Adjacency list of vertex 2  :  3
Adjacency list of vertex 3  :  1
Adjacency list of vertex 4  :  0  1
Adjacency list of vertex 5  :  0  2

Node [0] indegree [2] outdegree [3]
Node [1] indegree [3] outdegree [0]
Node [2] indegree [2] outdegree [1]
Node [3] indegree [1] outdegree [1]
Node [4] indegree [0] outdegree [2]
Node [5] indegree [1] outdegree [2]``````

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