基于javascript实现获取最短路径算法代码实例

这篇文章主要介绍了基于javascript实现获取最短路径算法代码实例,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下

代码如下

//A算法 自动寻路 路径
class GetAutoPath{

 constructor(id, map, sPos, ePos, mapArr){
  //this.type = id.type;
  this.id = id;
  this.map = map;
  this.sPos = sPos;
  this.ePos = ePos;
  this.mapArr = mapArr;
  this.maxMach = 10000;
  this.openArr = [];
  this.closeArr = [];
  this.minPath = [];
  if(!this.isPath(this.sPos.x, this.sPos.y)){this.sPos = this.getNewDot(sPos, ePos);}
  if(!this.isPath(this.ePos.x, this.ePos.y)){this.ePos = this.getNewDot(ePos, sPos);}
  //console.log(this.mapArr);
  return this.run();
 }

 posts(txt, arr){//post消息
  //let id = this.id, sPos = this.sPos, ePos = this.ePos, arrs = arr || [];
  return {id:this.id, map:this.map, arr:arr || [], sPos:this.sPos, ePos:this.ePos, txt:txt}
 }

 isPath(x, y){//isPath = true 合法路径 = isBanPath === undefined
  let isPath = false, ym = this.mapArr.get(y), xm; //console.log(ym); debugger;
  if(ym !== undefined){
   xm = ym.get(x);
   if(xm !== undefined){
    if(xm.isBanPath === undefined){isPath = true;}
   }
  }
  //if(this.mapArr[y] !== undefined && this.mapArr[y][x] !== undefined && this.mapArr[y][x].isPath === 1){isPath = true;}
  return isPath;
 }

 getEqual(arr, x, y){//获取目标数组相同的坐标
  let isPos = false;
  if(arr.length === 0){
   isPos = false;
  }else{
   isPos = arr.some(function (o){return o.x === x && o.y === y;});
  }
  return isPos;
 }

 getDot(x, y){//获取周围8个方向坐标
  return [{x:x-1,y:y},{x:x+1,y:y},{x:x,y:y-1},{x:x,y:y+1},{x:x-1,y:y-1},{x:x+1,y:y+1},{x:x+1,y:y-1},{x:x-1,y:y+1}]
 } 

 getNewDot(setPos, pos){//重定义起点或终点
  let dot = setPos, pointDot, k, arr = [], arrs = [], g, end, maxMachT = 0;
  while(!end && maxMachT < this.maxMach){
   maxMachT++;
   pointDot = this.getDot(dot.x, dot.y);
   for(k in pointDot){
    g = Math.round(Math.sqrt(Math.abs(pointDot[k].x - pos.x) + Math.abs(pointDot[k].y - pos.y)) * 100) / 100;
    if(!this.isPath(pointDot[k].x, pointDot[k].y)){//不合法
     arr.push({x:pointDot[k].x, y:pointDot[k].y, g:g});
     arr.sort(function(a, b){return a.g - b.g;});
    }else{//合法
     arrs.push({x:pointDot[k].x, y:pointDot[k].y, g:g});
     arrs.sort(function(a, b){return a.g - b.g;});
    }
    if(arrs.length > 0){end = true;}
   }
   dot = {x:arr[0].x, y:arr[0].y, g:arr[0].g}; arr = [];
  }
  if(!arrs[0].x || !arrs[0].y){return this.posts("没有符合的坐标");}
  return {x:arrs[0].x, y:arrs[0].y};
 }

 run(){
  if(this.sPos.x === undefined || this.ePos.x === undefined){return this.posts("没有符合的坐标");}
  let sPos = this.sPos, ePos = this.ePos, point, key, i, newPoint, ger, gers, g, h, f, maxMachT = 0;
  this.openArr[0] = {x : sPos.x, y : sPos.y, f : 0, p : 0, ger : 0}
  while(this.openArr.length > 0){
   maxMachT++;
   point = this.openArr[0]; this.closeArr.push(point); this.openArr.splice(0,1);
   key = this.closeArr.length - 1;//设置当前节点
   newPoint = this.getDot(point.x, point.y);//获取周围点
   for(i in newPoint){//设置周围点
    ger = Math.round(Math.sqrt(Math.abs(newPoint[i].x - point.x) + Math.abs(newPoint[i].y - point.y)) * 100) / 100;//到当前节点的曼哈顿距离,保留两位小数点
    gers = ger + point.ger;
    g = Math.round(gers * 100) / 100;
    h = Math.abs(newPoint[i].x - ePos.x) + Math.abs(newPoint[i].y - ePos.y);
    f = g + h;
    if(this.isPath(newPoint[i].x, newPoint[i].y) && !this.getEqual(this.openArr, newPoint[i].x, newPoint[i].y) && !this.getEqual(this.closeArr, newPoint[i].x, newPoint[i].y)){this.openArr.push({x:newPoint[i].x, y:newPoint[i].y, f:f, p:key, ger:ger});}
   }
   this.openArr.sort(function(a, b){return a.f - b.f;});//排序
   if(this.getEqual(this.closeArr, ePos.x, ePos.y) || this.getEqual(this.openArr, ePos.x, ePos.y)){//end
    this.minPath.unshift(this.closeArr[key]);
    while(this.minPath.length > 0){
     if(this.minPath[0].p == 0){return this.posts('success', this.minPath);}else{this.minPath.unshift(this.closeArr[this.minPath[0].p]);}
    }
   }else if(maxMachT === this.maxMach){
    return this.posts("没有符合的坐标");
   }
  }
  return this.posts("没有符合的坐标");
 }

}

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