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[Java教程]万事不求人系列之


作为一个成长中的架构师,编码能力是万不能停止的,这个算法是之前在上一家单位帮助同事们自助订餐写的,纯爱好自己码敲的,刚好这段时间重新整理代码,发现了它,分享给大家,请大家品评指教。

  1. 使用场景介绍:随着各种订餐APP的出现,找饭馆团购券,为自己订点好吃的或者团购固定人数的券都很方便,但是很多时候我们遇到的是这样的场景:知道用餐人数是几人,但是总经费或人均消费标准有限制,让你点菜,你就得一方面考虑荤素搭配,有菜有汤有主食,另一方面还得考虑经费限制;还有一种情况是就这么多总经费,人数又不确定(如之前答应去临走又有事告假的),人少可以多点几个硬菜,人多只能综合考虑,拿主食顶上。这两种场景,对点菜的人提出了很高的要求,本算法就是针对此种情况,只要给出用餐人数或固定金额,自动为你科学点菜,妈妈再也不用担心你是个点菜盲。
  2. 基本效果截图:

        

        如上图所示,输入人数点击开始点菜,系统自动会为你按照人均20的标准给出合理的菜单,这个人均标准是系统默认设置的,可以调整参数。如果输入人数的同时输入限定金额,则会以此金额为总花费的参考,保证不超过此金额下最优的给出建议菜单。当然如果同时输入了人数和限定金额,那么限定金额/人数不能低于系统设置的人均最低值,比如人数6人,限定金额50,人均很不到10块,下个毛管子。
    3.基本原理:根据人数或限定金额得到本次菜单的可用总金额,同时根据人数按照一定荤素比例计算各类菜需要的个数,如6个人需要三个肉菜,一个蔬菜,一个凉菜,6分主食。(这个菜个数的计算是随机的,凉菜随机出现,主食可以是米饭也可以是饺子之类的,这个也是随机的。同时蔬菜和肉菜的比例虽然固定,但是每次随机会有小的调整,有上下浮动。);得到每类菜的个数后开始从对应类别中随机选择,得到结果后按照金额的限制先排序再进行适当剔除或重选,使得总限定金额最优化,最后得到菜单并输出。
    4.核心JS函数解释说明:
    1. 初始化默认参数:
      1   var dishRate=[0.4,0.5,0.1]; // meat,vege,cold2   var leastAveragePayed = 10; // Average consumption money3   var defaultAveragePayed = 20; // default consumption money  4   var eatRiceFlag = true; // if eat rice or other things5   var eatRiceRate = 8; // the rate people eat rice;6   var eachRicePayed = 3; // each rice cost how much7   var moneyLimit = false;  8   var outRangeMoney = 5; // can over money
      9 var allDishArray = []; // 饭店所有的菜品

      基本参数有:荤蔬搭配比例、人均最少消费、默认人均消费、要米饭还是其他主食、要米饭的概率、每碗米饭的价钱、是否有总消费限制、上下浮动的空间、饭店所有的菜品(这个需要初始化,将菜品按荤蔬凉菜汤米饭等类别分开,具体代码没有贴上来,看附件里)

    2. 点击“开始点菜"执行的方式解释:
       1   function execute(){ 2     var peoples=eatPeoples.value; 3     var money=payMoney.value;     4     if("" == peoples){       5       resultMes.innerText = "请输入用餐人数!"; 6       return; 7     } 8     if(!/^\d+$/.test(peoples) || (("" != money) && !/^\d+$/.test(money))){     9       resultMes.innerText = "输入格式不对,请重新输入!";10       return;11     }12     if(""!=money.replace(/[\s]+/g,"")){13       moneyLimit = true;14     }15     randomChooseDish(peoples,money);    16   }

      做了一些基本的输入有效性验证,比如人数不能为空,输入格式校验等,然后进入randomChooseDish方法开始点菜

    3. randomChooseDish方法如下:
       1   function randomChooseDish(peoples,money){ 2     var tempPeoples=parseInt(peoples); 3     var tempSumMoney= (""==money)?tempPeoples*parseInt(defaultAveragePayed):parseInt(money);     4     if(!checkCondition(tempPeoples,tempSumMoney)){ 5       return; 6     } 7     var dishNumArray= getDishNumArray(tempPeoples); //get dishNumArray   8      9     var hasPayedMoney=0;  10     if(eatRiceFlag){11       // eat rice,reduce the rice money12       hasPayedMoney = eachRicePayed*tempPeoples;13     }  14 15     var beenChoosedArray = beginChooseDishesAndIndexs(dishNumArray);16     17     sortChoosedArray(beenChoosedArray);18     // when dishes are been choosed ,should check19     checkAndChangeDishes(beenChoosedArray,hasPayedMoney,tempSumMoney);  20     21     // show result22     showChooseResult(beenChoosedArray,hasPayedMoney,tempPeoples);    23   }

      确定人数和总金额,checkCondition做基本的条件判断,比如人数不能少于2人,总金额/人数不能低于人均最低值等;getDishNumArray用于根据人数和初始化荤素比例计算每类菜品需要点的数量;beginChooseDishesAndIndexs用于开始随机点菜;sortChoosedArray用于排序,从贵到便宜,这样对于便宜的菜可以有更多搭配的方式;checkAndChangeDishes用于对选择的菜进行金额限制检查,如果超过限制则开始从最便宜的菜调整菜,直到菜单合格;showChooseResult用于将结果显示到页面上。下面是具体每个函数的源码,有注释。

    4. checkCondition做基本的条件判断
       1   function checkCondition(tempPeoples,tempSumMoney){     2     if(tempPeoples<2){ 3       //alert(); 4       resultMes.innerText = "一个人下馆子?太奢侈了."; 5       return false; 6     } 7     if(tempPeoples>25){ 8       //alert(); 9       resultMes.innerText = "人数太多,一桌坐不下!";10       return false;11     }12 13     if(tempSumMoney<tempPeoples*leastAveragePayed){14       //alert();15       resultMes.innerText ="太抠了吧,都不到人均消费10块!";16       return false;17     }18     return true;19   }

       

    5. getDishNumArray用于根据人数和初始化荤素比例计算每类菜品需要点的数量
       1   // get meat,vege,cold numArray 2   function getDishNumArray(tempPeoples){ 3     var numArray=[Math.ceil(tempPeoples*dishRate[0]),getRandomRate(8)?Math.ceil(tempPeoples*dishRate[1]):Math.floor(tempPeoples*dishRate[1]),Math.round(tempPeoples*dishRate[2])]; // meat,vege,cold   4      5     if(getSumArray(numArray)<=tempPeoples+1 || tempPeoples>=10){ 6       var soupNum = Math.floor(tempPeoples/4) 7       numArray[numArray.length]=soupNum>2?2:soupNum; // add soup,soup num small then 2 8     } 9 10     eatRiceFlag = getRandomRate(eatRiceRate);11     if(!eatRiceFlag){12       // eat others13       var mainRiceNum = Math.floor(tempPeoples/3);14       numArray[numArray.length]=mainRiceNum>5?5:mainRiceNum; // add rice, mainrice nums small then 515     }16     return numArray;17   }

       

    6. beginChooseDishesAndIndexs用于开始随机点菜
       1   function beginChooseDishesAndIndexs(dishNumArray){ 2     var resultArray=[]; 3     var hasChoosedDishes=[]; // save be choosed dish 4     var hasChoosedIndexs=[]; // save be choosed in sourceArray index 5     var m = getRandom(dishNumArray.length); //random pos start 6     var dishLength=dishNumArray.length;     7     for(var i=0;i<dishLength;i++){ 8       var index = ((i+m)>=dishLength)?i+m-dishLength:(i+m); 9       var dishNum=dishNumArray[index];10       var tempSingleChoosed = []; // temp singleType choosed array      11       for(var n=0;n<dishNum;n++){12         var singleTypeArray = allDishArray[index];13         var singleTypeIndex = getRandom(singleTypeArray.length);  14         //alert(tempSingleChoosed+"and"+singleTypeIndex);15         while(tempSingleChoosed.length <= singleTypeArray.length && checkIfInArray(tempSingleChoosed,singleTypeIndex)){16           singleTypeIndex = getRandom(singleTypeArray.length); // if now index is choosed,choose again    17           //alert("reGet"+singleTypeIndex);18         }19         if(tempSingleChoosed.length == singleTypeArray.length){20           continue; // if singleTypeDish all been choosed, beak this circle,to next type dish21         }22         hasChoosedDishes[hasChoosedDishes.length] = singleTypeArray[singleTypeIndex]23         tempSingleChoosed[tempSingleChoosed.length] = singleTypeIndex; // ramark the temp position24         hasChoosedIndexs[hasChoosedIndexs.length] = index+","+singleTypeIndex; // ramark the position25       }26     } // all dish has choosed 27     resultArray.push(hasChoosedDishes);28     resultArray.push(hasChoosedIndexs);    29     return resultArray;30   }

       

    7. sortChoosedArray用于排序
       1   // when dishes been choosed ,sort it,from big to small 2   function sortChoosedArray(beenChoosedArray){   3     var hasChoosedDishes=beenChoosedArray[0]; // save be choosed dish 4     var hasChoosedIndexs=beenChoosedArray[1]; // save be choosed in sourceArray index     5     for(var i=0;i<hasChoosedDishes.length;i++){ 6       for(var j=i;j<hasChoosedDishes.length;j++){ 7         if(getDishAmount(hasChoosedDishes[i])>getDishAmount(hasChoosedDishes[j])){ 8           var temp = hasChoosedDishes[i]; 9           hasChoosedDishes[i] = hasChoosedDishes[j];10           hasChoosedDishes[j] = temp;11           // also should syn the choosedIndex12           var temp2 = hasChoosedIndexs[i];13           hasChoosedIndexs[i] = hasChoosedIndexs[j];14           hasChoosedIndexs[j] = temp2;15         }16       }17     }18     //alert(hasChoosedDishes);19   }

       

    8. checkAndChangeDishes用于对选择的菜进行金额限制检查
       1   // check if over money ,change less cost dish 2   function checkAndChangeDishes(beenChoosedArray,hasPayedMoney,tempSumMoney){   3       var outRange = moneyLimit?0:outRangeMoney; 4       while((hasPayedMoney+getSumArray(beenChoosedArray[0]))>tempSumMoney+outRange){         5         if(getRandomRate(8)){ 6           changeOneToLessExpensive(beenChoosedArray);// random choose one dish then change it to less expensive 7           sortChoosedArray(beenChoosedArray); // reSort 8         }else{ 9           removeDish(beenChoosedArray); // remove the most or least Expensive dish 10         }11       }              12     }

       

    9. showChooseResult用于将结果显示到页面上
       1   // show the choose result 2   function showChooseResult(beenChoosedArray,hasPayedMoney,tempPeoples){ 3     var hasChoosedDishes=beenChoosedArray[0]; // save be choosed dish 4     var hasChoosedIndexs=beenChoosedArray[1]; // save be choosed in sourceArray index 5     var tempcoldMes="凉菜:",tempVegeMes="蔬菜:",tempMeatMes="肉菜:",tempSoupMes="汤:",tempRiceMes="主食:";   6     for(var i in hasChoosedDishes){ 7       var choosedIndex = hasChoosedIndexs[i]; 8       var thisChoosedDish = hasChoosedDishes[i]; 9       var thisDishArray = thisChoosedDish.split("@");10       var allDishArrayIndex = (choosedIndex.split(","))[0];11       switch (allDishArrayIndex){12         case "0":tempMeatMes += thisDishArray[0]+":"+thisDishArray[1]+",";break;13         case "1":tempVegeMes += thisDishArray[0]+":"+thisDishArray[1]+",";break;14         case "2":tempcoldMes += thisDishArray[0]+":"+thisDishArray[1]+",";break;15         case "3":tempSoupMes += thisDishArray[0]+":"+thisDishArray[1]+",";break;16         case "4":tempRiceMes += thisDishArray[0]+":"+thisDishArray[1]+",";break;17         default:break;18       }19       hasPayedMoney += parseInt(thisDishArray[1]);20     }21     var resultMessage="";22     if(tempcoldMes.length>3){23       resultMessage += tempcoldMes.slice(0,-1)+"\n\n";24     }25     if(tempVegeMes.length>3){26       resultMessage += tempVegeMes.slice(0,-1)+"\n\n";27     }28     if(tempMeatMes.length>3){29       resultMessage += tempMeatMes.slice(0,-1)+"\n\n";30     }31     if(tempSoupMes.length>2){32       resultMessage += tempSoupMes.slice(0,-1)+"\n\n";33     }34     if(tempRiceMes.length>3){35       resultMessage += tempRiceMes.slice(0,-1)+"\n\n";36     }else if(eatRiceFlag){37       resultMessage += "主食:"+tempPeoples+"碗米饭("+eachRicePayed+"元/碗)"+"\n\n";38     }39     resultMessage += "共花费"+hasPayedMoney+"元"+"\n";40 41     resultMes.innerText = resultMessage;42   }


       其他都是一些辅助性的函数,见附件。
 
    5.附件点击下载: