Graph Adjacency List Representation in C

Any Body have Short and Simple Graph Adjacency List Representation code in C.

// A C Program to demonstrate adjacency list representation of graphs

#include <stdio.h>
#include <stdlib.h>

// A structure to represent an adjacency list node
struct AdjListNode
int dest;
struct AdjListNode* next;

// A structure to represent an adjacency liat
struct AdjList
struct AdjListNode *head;  // pointer to head node of list

// A structure to represent a graph. A graph is an array of adjacency lists.
// Size of array will be V (number of vertices in graph)
struct Graph
int V;
struct AdjList* array;

// A utility function to create a new adjacency list node
struct AdjListNode* newAdjListNode(int dest)
struct AdjListNode* newNode =
        (struct AdjListNode*) malloc(sizeof(struct AdjListNode));
newNode->dest = dest;
newNode->next = NULL;
return newNode;

// A utility function that creates a graph of V vertices
struct Graph* createGraph(int V)
struct Graph* graph = (struct Graph*) malloc(sizeof(struct Graph));
graph->V = V;

// Create an array of adjacency lists.  Size of array will be V
graph->array = (struct AdjList*) malloc(V * sizeof(struct AdjList));

 // Initialize each adjacency list as empty by making head as NULL
int i;
for (i = 0; i < V; ++i)
    graph->array[i].head = NULL;

return graph;

// Adds an edge to an undirected graph
void addEdge(struct Graph* graph, int src, int dest)
// Add an edge from src to dest.  A new node is added to the adjacency
// list of src.  The node is added at the begining
struct AdjListNode* newNode = newAdjListNode(dest);
newNode->next = graph->array[src].head;
graph->array[src].head = newNode;

// Since graph is undirected, add an edge from dest to src also
newNode = newAdjListNode(src);
newNode->next = graph->array[dest].head;
graph->array[dest].head = newNode;

// A utility function to print the adjacenncy list representation of graph
void printGraph(struct Graph* graph)
int v;
for (v = 0; v < graph->V; ++v)
    struct AdjListNode* pCrawl = graph->array[v].head;
    printf("\n Adjacency list of vertex %d\n head ", v);
    while (pCrawl)
        printf("-> %d", pCrawl->dest);
        pCrawl = pCrawl->next;

// Driver program to test above functions
int main()
// create the graph given in above fugure
int V = 5;
struct Graph* graph = createGraph(V);
addEdge(graph, 0, 1);
addEdge(graph, 0, 4);
addEdge(graph, 1, 2);
addEdge(graph, 1, 3);
addEdge(graph, 1, 4);
addEdge(graph, 2, 3);
addEdge(graph, 3, 4);

// print the adjacency list representation of the above graph

return 0;

Source: geeksforgeeks

#define pb push_back
vector adj[MAXN]
vector weg[MAXN];
void addEdge(int a,int b,int w)

Is this enough?

This is C++ . User is asking in C.

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