Instance programming: Maze Pathfinder III

Consider a tree from the maze entrance to the shortest path near the point. The shortest path near the exit can be found by means of breadth traversal. The algorithm idea of this program originates from the Dijkstra algorithm of finding the shortest path near the other points in the graph.

/* Maze Pathfinder III (Shortest path) * *

/* Dijkstramaze. C * * *

* 2003-8-26 * *

#include <stdlib.h>

#include <time.h>

#include <math.h>

#include <stdio.h>

#include <graphics.h>

#define N 22

#define M 22

int bg[m][n];

int aa[m][n];

struct pace{

int pre;

int x;

int y;

int ri;

int RJ;

}road[m*n];

struct pace bestroad[m*n];

void Makebg (Int,int);

void Drawbg (Int[][],int,int,int,int,int);

void Drawman (Int,int,int);

void rect (int,int,int,int);

void Main () {*/* Main () starts/*

int step=20;

int len=10;

int size=20;

int x=0,y=0;

int i=0,j=0;

int Gdriver=detect,gmode;

Char ch;

int Direc;

int routelen=0;

int dj[]={-1,1,0,0};

int di[]={0,0,-1,1};

int begin;

int end;

int k;

int t;

int num;

int suc;

int cnt;

int x0;

int y0;

int le;

int tmp;

MAKEBG (M,n);

/* Registerbgidriver (Egavga_driver);

Initgraph (&gdriver,&gmode, "c:\turboc2");

Initgraph (&gdriver,&gmode, "C:\TC20\BGI");

Cleardevice ();

Setwritemode (Xor_put);

Settextstyle (1,0,3);

SetColor (GREEN);

Outtextxy (100,180, "DIJKSTRA MAZE");

SetColor (BLUE);

Setfillstyle (Line_fill,blue);

/*DRAWBG (bg,m,n,size,0,0);

DRAWBG (aa,m,n,size,0,0);

SetColor (white);

X+=len;y+=len;

Drawman (X,y,len);

X0=x;y0=y;

/* Computer control *

i=j=0;

Aa[0][0]=1;

begin=0;

End=0;

road[0].ri=0;

road[0].rj=0;

road[0].x=x0;

Road[0].y=y0;

Road[0].pre=-1;

le=1;

suc=0;

while (!SUC) {

cnt=0;

le++;

for (k=begin;k<=end;k++) {

for (t=0;t<4;t++) {

X=road[k].x+dj[t]*step;

Y=road[k].y+di[t]*step;

I=ROAD[K].RI+DI[T];

J=ROAD[K].RJ+DJ[T];

if (i<m&&i>=0&&j<n&&j>=0&&aa[i][j]==0) {

cnt++;

Aa[i][j]=le;

Road[end+cnt].pre=k;

Road[end+cnt].x=x;

Road[end+cnt].y=y;

Road[end+cnt].ri=i;

Road[end+cnt].rj=j;

if (i==n-1&&j==m-1) {

Suc=1;

Break

}

}

}

if (suc) break;

}

begin=end+1;

end=end+cnt;

}

/* Output */

i=end;j=0;

while (I!=-1) {

bestroad[j].x=road[i].x;

BESTROAD[J].Y=ROAD[I].Y;

Bestroad[j].ri=road[i].ri;

BESTROAD[J].RJ=ROAD[I].RJ;

I=road[i].pre;

j + +;

}

for (i=0;i<j/2;i++) {

tmp=bestroad[i].x;

bestroad[i].x=bestroad[j-1-i].x;

bestroad[j-1-i].x=tmp;

TMP=BESTROAD[I].Y;

BESTROAD[I].Y=BESTROAD[J-1-I].Y;

bestroad[j-1-i].y=tmp;

}

Getch ();

Drawman (X0,y0,len);

for (i=0;i<j;i++) {

Drawman (Bestroad[i].x,bestroad[i].y,len);

Delay (80000);

Drawman (Bestroad[i].x,bestroad[i].y,len);

}

i--;

Drawman (Bestroad[i].y,bestroad[i].x,len);

Getch ();

Closegraph ();

}

/* Main () End/*

* * Draw Villain * *

void Drawman (int x,int y,int len) {

int R=LEN/4;

Rect (X-R,Y-LEN,X+R,Y-LEN+2*R);

Line (x,y-len+2*r,x,y);

Line (x-len,y,x+len,y);

Line (X,y,x-len,y+len);

Line (X,y,x+len,y+len);

}

* * Draw Maze Map * *

void drawbg (int bg[][n],int a,int b,int size,int x,int y) {

int startx=x;

int i,j;

for (i=0;i<a;i++) {

for (j=0;j<b;j++) {

if (bg[i][j]==-1)

Rect (x,y,x+size-1,y+size-1);

X+=size;

}

X=startx;

Y+=size;

}

Rectangle (0,0,size*b,size*a);

Line (0,0,size,0), line (0,0,0,size);

Line (size*b,size* (A-1), size*b,size*a);

Line (size* (b-1), size*a,size*b,size*a);

}

/* Draw a solid rectangle * *

void rect (int x0,int y0,int x1,int y1) {

int i,j;

for (i=x0;i<=x1;i++)

Line (I,Y0,I,Y1);

}

/* random generation to represent the maze map of the array * *

void Makebg (int a,int b) {

int i,j;

int ran;

int Direc;

/* Initialize MAZE map * *

for (i=0;i<a;i++)

for (j=0;j<b;j++)

Bg[i][j]=1;

/* Randomly generated maze path * *

Randomize ();

i=j=0;direc=2;

while (1) {

bg[i][j]=0;

if (i>=m-1&&j>=n-1) break;

ran= (int) rand () *4;

if (ran<1) {

if (direc!=1&&i<a-1) {

i++;

direc=3;

}

}

else if (ran<2) {

if (direc!=2&&j>0) {

j--;

direc=0;

}

}

else if (ran<3) {

if (direc!=3&&i>0) {

i--;

Direc=1;

}

}

else {

if (direc!=0&&j<b-1) {

j + +;

direc=2;

}

}

}

* * Randomly generated maze rest part

for (i=0;i<a;i++)

for (j=0;j<b;j++)

if (bg[i][j]==1) {

ran= (int) rand () *10;

if (ran<5) bg[i][j]=0;

}

for (i=0;i<a;i++)

for (j=0;j<b;j++) {

if (bg[i][j]==1) aa[i][j]=-1;

else aa[i][j]=0;

}

}