2015年03月09日 蛋炒饭

[think2011]

你是一家快餐店的老板，每天营业前，你需要根据采购的食材来确定今天能够做多少份快餐：

// 炒蛋饭食谱
var fryRice = {
 rice: 1,
 egg: 1,
 meat: 2
}

// 食材
var material = {
 rice: 10, // 100
 egg: 10, // 100
 meat: 5 // 50
}

function check (food, material) {
 // 请完成这个代码
}

console.log(check(fryRice, material)); 
// 结果： {sum: 2, remnants: {rice: 8, egg: 8, meat: 1}}

[LetroLiu]

 var obj={},
 remnants={},
 o,
 i=0;
 for(o in food){
 i=material[o];
 break;
 }
 for(o in food){
 obj[o]=parseInt(material[o]/food[o]);
 i=i>obj[o]?obj[o]:i;
 }
 for(o in food){
 remnants[o]=material[o]-food[o]*i;
 }
 return {sum:i,remnants:remnants};

[XadillaX]

function check (food, material) {
 return (function(v) {
 return { sum: v, remnants: Object.keys(food).reduce(function(res, i) {
 return res[i] = material[i] - v * food[i], res;
 }, {}) };
 })(Object.keys(food).reduce(function(res, i) {
 return Math.min(res, parseInt(material[i] / food[i]));
 }, Number.MAX_VALUE));
}

还是老风格，不带 if，for 和 var。

[VaJoy]

 function check (food, material) {
 var flag = !1,
 sum = 0,
 remnants = {};
 Object.keys(food).forEach(function(key){
 if(!material[key]||material[key]<food[key]) flag=!0;
 sum = !sum?((material[key]/food[key])|0):Math.min(sum,(material[key]/food[key])|0);
 });
 if(flag) return {sum:0,remnants:material};
 Object.keys(material).forEach(function(key){
 remnants[key] = material[key] - sum*(food[key]||0)
 });
 return {sum:sum,remnants:remnants}
 }

才发现在forEach里return的话是不会终止函数甚至不会终止循环的，还不如用一楼的for in

[VaJoy]

ES6来帮忙，这样效率高一点，sum=0的时候直接return不再执行

function check (food, material) {
 var sum = 0,
 remnants = {};
 for(var key of Object.keys(food)){
 if(!material[key]||material[key]<food[key]) return {sum:0,remnants:material};
 sum = !sum?((material[key]/food[key])|0):Math.min(sum,(material[key]/food[key])|0);
 }
 Object.keys(material).forEach(function(key){
 remnants[key] = material[key] - sum*(food[key]||0)
 });
 return {sum:sum,remnants:remnants}
}

[think2011]

@VaJoy 咦，哪里用到了ES6的特性，感兴趣！

[VaJoy]

@think2011 for of

[lichengzhou]

弄一个不太好的：

function check (food, material) {
 // 请完成这个代码
 var sum = null;
 for(var prop in material){
 if(material.hasOwnProperty(prop) && food[prop]){
 var temp = parseInt(material[prop]/food[prop]);
 sum = sum == null? temp: (temp > sum ? sum : temp);
 }
 }

 var remnants = {};
 for(var prop in material){
 if(material.hasOwnProperty(prop)){
 remnants[prop] = material[prop] - (food[prop] ? food[prop]*sum : 0);
 }
 }

 return {
 sum: sum,
 remnants: remnants
 };
}

[PeakFish]

来个递归版

function check (food, material) {
 // 请完成这个代码
 var sum = 0;
 function reducematerial(material){
 if(material.rice < 1 || material.egg < 1 || material.meat < 2){
 return;
 }else{
 ++sum;
 material.rice -= 1;
 material.egg -= 1;
 material.meat -= 2;
 reducematerial(material);
 }
 }
 reducematerial(material);
 return {sum: sum, remnants: material};
}