1.什么是图？

2.图的抽象数据结构

3.如何在程序中表示一个图？

3.1 邻接矩阵

3.2 邻接表

4.图的遍历

4.1 深度优先搜索

4.2 广度优先搜索

5.图的C语言实现

#include<stdio.h>
#include<stdlib.h>#define WeightType int
#define MaxVertexNum 3
typedef struct GNode *PtrToGNode;
typedef PtrToGNode MGraph;
typedef int Vertex;
typedef struct ENode *PtrToENode;
typedef PtrToENode Edge;struct GNode{int Nv;  //顶点数int Ne;  //边数WeightType G[MaxVertexNum][MaxVertexNum];
};
struct ENode{Vertex V1,V2;WeightType Weight;
};//1.初始化
MGraph CreateGraph(int VertexNum)
{Vertex V,W;MGraph Graph;Graph=(MGraph)malloc(sizeof(struct GNode));Graph->Nv=VertexNum;Graph->Ne=0;for(V=0;V<Graph->Nv;V++){for(W=0;W<Graph->Nv;W++){Graph->G[V][W]=0;}}return Graph;
}//2.插入边
void InsertEdge(MGraph Graph,Edge E)
{//插入边<V1,V2>Graph->G[E->V1][E->V2]=E->Weight;//无向图，还要插入<V2,V1>Graph->G[E->V2][E->V1]=E->Weight;
}int main()
{int i,j;MGraph Graph;Edge E[3];Graph=CreateGraph(3);for(i=0;i<3;i++){for(j=0;j<3;j++){printf("G[%d][%d]=%d  ",i,j,Graph->G[i][j]);}}printf("\n");for(i=0;i<3;i++){E[i]=(Edge)malloc(sizeof(struct ENode));}E[0]->V1=0;E[0]->V2=1;E[0]->Weight=2;E[1]->V1=1;E[1]->V2=2;E[1]->Weight=3;E[2]->V1=0;E[2]->V2=2;E[2]->Weight=6;for(i=0;i<3;i++){InsertEdge(Graph,E[i]);}for(i=0;i<3;i++){ for(j=0;j<3;j++){printf("G[%d][%d]=%d  ",i,j,Graph->G[i][j]);}}printf("\n");return 0;
}