第2个回答 2013-07-24
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <iomanip>
#include <string>
#define MAX_VERTEX_NUM 99
#define NULL 0
int i,j;
using namespace std;typedef struct Arcnode
{
char adjvex;
int number;
struct Arcnode *nextarc;
int time;
}Acrnode;typedef struct VNode
{
char data;
Acrnode *firstarc;
}VNode,Adjlist[MAX_VERTEX_NUM];typedef struct
{
Adjlist vertices;
int vexnum,arcnum;
}ALGraph;typedef struct
{
int *base;
int *top;
int stacksize;
}Sqstack;void exampleout()
{
ifstream fin;
ofstream fout;fin.open("example.txt");
if(fin.fail())
{
cout << "Input file opening failed.\n";
exit(1);
}
char a;
fin.get(a);
while(!fin.eof())
{
cout << a;
fin.get(a);
}
fin.close();
}void print()
{
ifstream fin;
ofstream fout;fin.open("result.txt");
if(fin.fail())
{
cout << "Input file opening failed.\n";
exit(1);
}
char a;
fin.get(a);
while(!fin.eof())
{
cout << a;
fin.get(a);
}
fin.close();
}int number(string b)//将数字字符串转化为对应的数字
{
int flag,num,number=0;
int m,n;
flag=b.length();
for(m=0;m<flag;m++)
{
num=b[m]-48;
for(n=0;n<flag-m-1;n++)
num=num*10;
number=number+num;
}
return number;
}void datain(ALGraph *G)
{
Acrnode *p,*q;
i=0; j=0;
char a; string b;ifstream fin;
ofstream fout;fin.open("data.txt");
if(fin.fail())
{
cout << "Input file opening failed.\n";
exit(1);
}fin.get(a);
while(a!='\n')
{
G->vertices[i].data=a;
//cout << G->vertices[i].data;
fin.get(a);
i++;
G->vexnum=i;
}G->arcnum=0;for(j=0;j<G->vexnum;j++)
{
fin.get(a);
if(a!='\n')
{
G->vertices[j].firstarc=(Acrnode *)malloc(sizeof(Acrnode));
G->vertices[j].firstarc->adjvex=a;
G->vertices[j].firstarc->nextarc=NULL;
//cout << G->vertices[j].data << G->vertices[j].firstarc->adjvex;
getline(fin,b,' ');
G->vertices[j].firstarc->time=number(b);
G->arcnum++;
//cout << G->vertices[j].firstarc->time;
q=G->vertices[j].firstarc;
fin.get(a);
while(a!='\n')
{
p=(Acrnode *)malloc(sizeof(Acrnode));
p->adjvex=a;
//cout << p->adjvex;
p->nextarc=NULL;
q->nextarc=p;
q=p;
getline(fin,b,' ');
p->time=number(b);
G->arcnum++;
//cout << p->time;
fin.get(a);
}
}
}
//cout << G->arcnum;
fin.close();
}void Findindegree(ALGraph G, int indegree[])
{
char x; Acrnode *r;
for(i=0;i<G.vexnum;i++)
{
x=G.vertices[i].data;
for(j=0;j<G.vexnum;j++)
{
r=G.vertices[j].firstarc;
while(r!=NULL)
{
if(r->adjvex==x) {indegree[i]++;r->number=i;r=NULL;}
else r=r->nextarc;
}
}
//cout << indegree[i];
}
}void Initstack(Sqstack &S)
{
S.base=(int *)malloc(MAX_VERTEX_NUM * sizeof(int));
S.top=S.base;
S.stacksize=MAX_VERTEX_NUM;
}int Stackempty(Sqstack S)
{
if(S.top==S.base) return 1;
else return 0;
}void Push(Sqstack &S,int x)
{
*S.top=x;
S.top++;
}
void Pop(Sqstack &S,int &x)
{
x=*--S.top;
}void Topologicalsort(ALGraph G,int indegree[])
//有向图G采用邻接表存储结构。
//若G无回路，则输出G的顶点的一个拓扑序列,否则返回ERROR。
{
Findindegree(G,indegree); //对各个顶求入度indegree[0..vernum-1]
Acrnode *p; int count,k;
Sqstack S;
Initstack(S);
for (i=0;i<G.vexnum;++i) //建零入度顶点栈S
if(!indegree[i]) Push(S,i); //入度为0者入栈
count=0; //对输出顶点计数
while(!Stackempty(S))
{
Pop(S,i);
//cout << G.vertices[i].data; //输出i号顶点并计数
++count;
for(p=G.vertices[i].firstarc; p; p=p->nextarc)
{
k=p->number; //对i号顶点的每个邻接点的入度减1
if(!(--indegree[k])) Push(S,k); //若入度减为0，则入栈
}
}
if(count<G.vexnum) cout << "ERROR!该工程不能顺利完成！"; //该有向图有回路
else cout << "Ready!该工程可以顺利完成！" << endl;
}void Topologicalorder(ALGraph G,Sqstack &T,int indegree[],int ve[])
//有向网G采用邻接表存储结构，求各顶点事件的最早发生时间ve
//T为拓扑排序顶点栈，S为零入度顶点栈。
//若G无回路，则用栈T返回G的一个拓扑序列，且函数值为OK，否则为ERROR。
{
Findindegree(G,indegree); //对各个顶求入度indegree[0..vernum-1]
Acrnode *p; int count,k;
Sqstack S;
Initstack(S);
for (i=0;i<G.vexnum;++i) //建零入度顶点栈S
if(!indegree[i]) Push(S,i); //入度为0者入栈
count=0; //对输出顶点计数
while(!Stackempty(S))
{
Pop(S,j);
Push(T,j);
++count; //j号顶点入T栈并计数
for(p=G.vertices[j].firstarc; p; p=p->nextarc)
{
k=p->number; //对i号顶点的每个邻接点的入度减1
if(!(--indegree[k])) Push(S,k); //若入度减为0，则入栈
if(ve[j]+p->time>ve[k]) ve[k]=ve[j]+p->time;
}
}
//for (i=0;i<G.vexnum;++i)
//cout << ve[i];
ofstream fout;
fout.open("result.txt");
fout.close();if(count<G.vexnum) cout << "ERROR"; //该有向图有回路
}void result(int a[],int b[],ALGraph G,int ve[],int vl[])
{
ofstream fout;
fout.open("result.txt");
fout << "工程的最短耗时为： " << ve[G.vexnum-1] << endl;
fout << "关键活动 最早开始时间 最晚开始时间" << endl;
for(j=0;j<i;j++)
{
fout << " <" << G.vertices[a[j]].data << "," << G.vertices[b[j]].data << "> ";
fout << ve[a[j]] << " " << ve[b[j]] << " ";
fout << vl[a[j]] << " " << vl[b[j]] << " " << endl;
}
fout.close();
}void Criticalpath(ALGraph G,int indegree[],int ve[],int vl[])
{
int a[MAX_VERTEX_NUM]={0};
int b[MAX_VERTEX_NUM]={0};
Sqstack T;
Initstack(T);
Topologicalorder(G,T,indegree,ve);
Acrnode *p;int k,dut,ee,el;
for(i=0;i<G.vexnum;++i)
vl[i]=ve[G.vexnum-1]; //初始化顶点时间的最迟发生时间
while(!Stackempty(T)) //按逆拓扑排序求各顶点的vl值
{
for(Pop(T,j),p=G.vertices[j].firstarc; p; p=p->nextarc)
{
k=p->number; dut=p->time;
if(vl[k]-dut<vl[j]) vl[j]=vl[k]-dut; //dut<j,k>
}
}
i=0;
for(j=0;j<G.vexnum;++j) //求ee，el和关键活动
for(p=G.vertices[j].firstarc;p;p=p->nextarc)
{
k=p->number; dut=p->time;
ee=ve[j]; el=vl[k]-dut;
if(ee == el)
{a[i]=j;b[i]=k;i++;} //输出关键活动
}
result(a,b,G,ve,vl);
}int main()
{ALGraph G; int ddy; char bye;
for(j=0;j<MAX_VERTEX_NUM;j++) {G.vertices[j].data=0;G.vertices[j].firstarc=NULL;}
int indegree[MAX_VERTEX_NUM]={0};
int ve[MAX_VERTEX_NUM]={0};
int vl[MAX_VERTEX_NUM]={0};
cout << "WELLCOME!本程序将计算工程的最短耗时和关键路径" << endl;
do
{
cout << endl << "请选择：" << endl;
cout << "1.查看数据文件示例文本" << endl;
cout << "2.检查输入的工程能否顺利完成" << endl;
cout << "3.计算工程的最短耗时和关键路径并生成文本文件" << endl;
cout << "4.显示计算结果" << endl;
cout << "0.退出" << endl << endl;
cin >> ddy;
switch(ddy)
{
case 1:exampleout();break;
case 2:{datain(&G); Topologicalsort(G,indegree);}break;
case 3:Criticalpath(G,indegree,ve,vl);break;
case 4:{print();cout << endl;}break;
case 0:cout << "再见！";break;
}
}while(ddy!=0);
cin.get(bye);
cin.get(bye);
return 0;
}data.txtABCDEFGHI
B6 C4 D5
E1
E1
F2
G9 H7
H4
I2
I4
example.txtABCDEFGHI（事件代号）
B6 C4 D5 （每个事件的后继事件及活动时间）
E1 (每个数字后空格)
E1
F2
G9 H 7
H4
I2
I4本回答被网友采纳