Example of the shortest path for C + + queries

This article mainly introduces the C + + query Shortest Path example, the need for friends can refer to the following

The code is as follows:

Shortest_path.c

#include

#include//with file

#include//Available gets (), puts ()

#include "shortest_path.h"

#define MAX 32767

#define MENU "Welcome to the navigation system!n========== menus ===========n0, loading the map n1, building maps N2, query the shortest path N3, exit n========== menu ===========n"

struct Stmap map;//without network

const char *filepath1= "D:spots.dat";

const char *filepath2= "D:paths.dat";

int Load1 ()

{

FILE *FP;

int i;

Fp=fopen (Filepath1, "R");

if (fp==null) {printf ("Spots file open exception, read failed"); return-1}

Fread (&map.spotnum,sizeof (int), 1,FP);

for (i=0;i

{

Fread (Map.spot[i].name,sizeof (char), 10,FP);

Fread (Map.spot[i].intro,sizeof (char), 20,FP);

}

Fclose (FP);

return 0;

}

int Load2 ()

{

FILE *FP;

int i,j;

Fp=fopen (Filepath2, "R");

if (fp==null) {printf ("Paths file open exception, read failed"); return-1}

Fread (&map.pathmatrix,sizeof (int), 1,FP);

for (i=0;i

for (j=0;j

Fread (&map.pathmatrix[i][j],sizeof (int), 1,FP);

Fclose (FP);

return 0;

}

void Loadmap ()

{

if (Load1 () ==0)

printf ("Spot reads success n");

Else

printf ("spot reads failed n");

if (Load2 () ==0)

printf ("Path reads success n");

Else

printf ("path reads failed n");

}

void Drawmap ()/Direct input

{

int i;

int a,b;

Char s1[10],s2[10];

printf ("How many attractions are there?" ( <=20) ");//map.spotmun

Fflush (stdin);

scanf ("%d", &map.spotnum);

printf ("A direct link between several attractions and attractions"); /map.pathnum

Fflush (stdin);//empty keyboard buffer, in "stdio.h"

scanf ("%d", &map.pathnum);

for (a=0;a

for (b=0;b

{

if (a==b) map.pathmatrix[a][b]=0;

else Map.pathmatrix[a][b]=max;

}

for (i=0;i

printf ("Please enter the name of the first%d attractions (<=10letters)", i+1);

Fflush (stdin);

Gets (Map.spot[i].name);

printf ("Please enter the introduction of the first%d attractions (<=20letters)", i+1);

Fflush (stdin);

Gets (Map.spot[i].intro);

}//Enter the name and description of the attraction Map.spot[].name;map.spot[].intro

for (i=0;i

do{

printf ("Please enter the start of the%d path", i+1);

Fflush (stdin);

Gets (S1);

for (a=0;a

if (!strcmp (MAP.SPOT[A].NAME,S1)) break;//Find the spot number

if (a==map.spotnum) printf ("Does not exist, please re-enter it.") n ");

}while (A==map.spotnum);

do{

printf ("Please enter the end of page%d path", i+1);

Fflush (stdin);

Gets (S2);

for (b=0;b

if (!strcmp (MAP.SPOT[B].NAME,S2)) break;

if (b==map.spotnum) printf ("Does not exist, please re-enter it.") n ");

}while (B==map.spotnum);

printf ("Please enter the length of section%d path", i+1);

Fflush (stdin);

scanf ("%d", &map.pathmatrix[a][b]);

map.pathmatrix[b][a]=map.pathmatrix[a][b];//Input Path length

}

}

void Shortestpath ()//Shortest path, enter start point end output path and distance

{

struct Stspath spath[20];

int s,t,v,w,min;

Char s1[10],s2[10];

int pathorder[20];

struct Stspath *p;//pathorder

do{

printf ("Please enter a starting point");//Find the spot number for the starting point

Fflush (stdin);

Gets (S1);

for (s=0;s

if (!strcmp (MAP.SPOT[S].NAME,S1)) break;

if (s==map.spotnum) printf ("Does not exist, please re-enter it.") n ");

}while (S==map.spotnum);

do{

printf ("Please enter End");//Find the destination number for the end point

Fflush (stdin);

Gets (S2);

for (t=0;t

if (!strcmp (MAP.SPOT[T].NAME,S2)) break;

if (t==map.spotnum) printf ("Does not exist, please re-enter it.") n ");

}while (T==map.spotnum);

for (v=0;v

{

Spath[v].length=max;

spath[v].in=0;

}

Spath[s].in=1;

spath[s].length=0;

Spath[s].pior=null;

V=s;

while (v!=t) {

for (w=0;w

if ((!spath[w].in) && (Spath[w].length>spath[v].length+map.pathmatrix[v][w])) {

SPATH[W].LENGTH=SPATH[V].LENGTH+MAP.PATHMATRIX[V][W];

spath[w].pior=&spath[v];

}

Min=max;

for (w=0;w

if ((!spath[w].in) && (spath[w].length

Min=spath[w].length;

V=w;

}

Spath[v].in=1;

}

printf ("Shortest path length is%d, shortest path is: n", spath[t].length);//print Path

For (V=0,p=&spath[t];p->pior!=null;p=p->pior)

{

Pathorder[v]=p-spath;

v++;

}

Pathorder[v]=s;

for (; v>=0;v--)

printf ("%10s", map.spot[pathorder[v]].name);

}

void Main ()

{

int menu=1;

printf (MENU);

while (menu!=3)

{

printf ("N Please enter your option (number) n");

Fflush (stdin);

scanf ("%d", &menu);

Switch (menu)

{

Case 0:loadmap ();p rintf ("N map loading n");

Case 1:drawmap ();p rintf ("N New Complete n");

Case 2:shortestpath ();p rintf ("N query complete n");

}

}

printf ("Thank you for using!");

}

2. [File] shortest_path.h ~ 430B Download (2)

#ifndef _shortest_path_h_

#define _shortest_path_h_

Vertices of struct stspot{//sights

Char name[11];//attractions name no more than 10

Char intro[20];//Attractions Introduction no more than 20

};

struct stmap{//whole non-direction net

Stspot spot[20];//dot, attraction vector

int pathmatrix[20][20];//edge, path adjacency matrix

int spotnum;

int pathnum;

};

struct stspath//An array of sights when seeking the shortest path

{

Stspath * PIOR;

int in;//can be Boolen

int length;

};

#endif

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