Ice Cream Purchases

ice-cream-purchase.js

// https://www.hackerrank.com/challenges/ctci-ice-cream-parlor
// find 2 distinct flavors that would take up all of the money m

// for each trip print the id numbers of the two types of ice cream
// some ice creams may have the same price


function purchase(indexed, product) {
    let result = Object.assign({}, indexed);

    if(result[product.value]) {
       result[product.value] = result[product.value].filter(p => p !== product) 
    }
    return result;
}

function purchaseTwo(cash, products, purchases=[]) {
    let indexed = products.reduce((tot, next) => {
        if(!tot[next.value]) {
            tot[next.value] = [];
        }
        tot[next.value].push(next)
        return tot;
    }, {});

    for(let product of products) {
        let cashRemaining = cash - product.value;

        let remainingProducts = purchase(indexed, product);
        
        if(remainingProducts[cashRemaining]) {
            return [product, remainingProducts[cashRemaining][0]];
            break;
        }
    }
}


let input = `2
4
5
1 4 5 3 2
4
4
2 2 4 3`;

let lines = input.split('\n');
let numTrips = parseInt(lines.shift());

while(lines.length) {
    let purchasePower = parseInt(lines.shift());
    let numProducts = parseInt(lines.shift());
    let products = lines.shift().trim().split(' ').map((value, index) => ({id: index+1, value: parseInt(value)})).sort((a,b) => {
        return a.value - b.value;
    });

    console.log(purchaseTwo(purchasePower, products).map(product => product.id).sort((a,b) => a-b).join(' '));
}

//output
// 1 4
// 1 2