# Write a suitable declaration for a graph ADT interface that can be used to study graph algorithms

**Source Code**

Brief explanation is provided after the source code.

/* Graph ADT interface (graph.h) */ typedef struct { int v; int w; } Edge; Edge EDGE(int, int); typedef struct graph *Graph; /* implementation of struct graph varies */ Graph GraphInit(int); void GraphInsertE(Graph, Edge); void GraphRemoveE(Graph, Edge); int GraphEdges(Edge[], Graph G); /* extract the set of edges in an array */

**Brief Explanation**

- Simple interface that can be used to study graphs algorithms.
- Data type Edge represents an edge (i.e a vertex pair)
- Function EDGE takes an integer pair representing two vertex values, and makes and return an edge from them. User defined data type Graph is a pointer to a graph data structure, which is implementation-dependent.
- Functions GraphInit, GraphInsertE, and GraphRemoveE respectively initializes the graph, inserts an edge, and removes an edge, while function GraphEdges extracts the set of edges in an array.