Description
Write a program to find the topological order in a digraph.
Format of functions:
bool TopSort( LGraph Graph, Vertex TopOrder[] );
where LGraph is defined as the following:
typedef struct AdjVNode *PtrToAdjVNode;
struct AdjVNode{
Vertex AdjV;
PtrToAdjVNode Next;
};
typedef struct Vnode{
PtrToAdjVNode FirstEdge;
} AdjList[MaxVertexNum];
typedef struct GNode *PtrToGNode;
struct GNode{
int Nv;
int Ne;
AdjList G;
};
typedef PtrToGNode LGraph;
The topological order is supposed to be stored in TopOrder[] where TopOrder[i] is the i-th vertex in the resulting sequence. The topological sort cannot be successful if there is a cycle in the graph -- in that case TopSort must return false; otherwise return true.
Notice that the topological order might not be unique, but the judge's input guarantees the uniqueness of the result.
Sample program of judge:
#include
#include
typedef enum {false, true} bool;
#define MaxVertexNum 10 /* maximum number of vertices */
typedef int Vertex; /* vertices are numbered from 0 to MaxVertexNum-1 */
typedef struct AdjVNode *PtrToAdjVNode;
struct AdjVNode{
Vertex AdjV;
PtrToAdjVNode Next;
};
typedef struct Vnode{
PtrToAdjVNode FirstEdge;
} AdjList[MaxVertexNum];
typedef struct GNode *PtrToGNode;
struct GNode{
int Nv;
int Ne;
AdjList G;
};
typedef PtrToGNode LGraph;
LGraph ReadG(); /* details omitted */
bool TopSort( LGraph Graph, Vertex TopOrder[] );
int main()
{
int i;
Vertex TopOrder[MaxVertexNum];
LGraph G = ReadG();
if ( TopSort(G, TopOrder)==true )
for ( i=0; iNv; i++ )
printf(
Input
where LGraph is defined as the following:
typedef struct AdjVNode *PtrToAdjVNode;
struct AdjVNode{
Vertex AdjV;
PtrToAdjVNode Next;
};
typedef struct Vnode{
PtrToAdjVNode FirstEdge;
} AdjList[MaxVertexNum];
typedef struct GNode *PtrToGNode;
struct GNode{
int Nv;
int Ne;
AdjList G;
};
typedef PtrToGNode LGraph;
The topological order is supposed to be stored in TopOrder[] where TopOrder[i] is the i-th vertex in the resulting sequence.
Output
where LGraph is defined as the following:
typedef struct AdjVNode *PtrToAdjVNode;
struct AdjVNode{
Vertex AdjV;
PtrToAdjVNode Next;
};
typedef struct Vnode{
PtrToAdjVNode FirstEdge;
} AdjList[MaxVertexNum];
typedef struct GNode *PtrToGNode;
struct GNode{
int Nv;
int Ne;
AdjList G;
};
typedef PtrToGNode LGraph;
The topological order is supposed to be stored in TopOrder[] where TopOrder[i] is the i-th vertex in the resulting sequence.
5 7
1 0
4 3
2 1
2 0
3 2
4 1
4 2