Mini-Max Sum

 

 

Problem

Given five positive integers, find the minimum and maximum values that can be calculated by summing exactly four of the five integers. Then print the respective minimum and maximum values as a single line of two space-separated long integers.

 

Example

let arr = [1, 3, 5, 7, 9]

 

The minimum sum is  1 + 3 + 5 + 7 = 16 and the maximum sum is 3 + 5 + 7 + 9 = 24. The function prints

 

16 24

 

 

 

 

Solution 1

const arr = [3,1,4,2,5]

function miniMaxSum(arr) {
    let sum = [];
    for (let i = 0; i < arr.length; i++) {
        //The callback function takes three arguments: current element, index of that element, array itself
        //index and array arguments are optional.
        let filtered = arr.filter((value, index, arr) => {
            return i !== index; //자기자신의 index 를 제외하고 sum해야하는 condition 이 true일때 동작.
        });
        sum.push(filtered.reduce((accumulator, current) => accumulator + current));
    }
    console.log(Math.min(...sum) + " " + Math.max(...sum));
}

miniMaxSum(arr); //10 14

//What I learned from this Algorithm.
//how filter() works. how filter() can reduce the code.
//filter method returns array

 

sort() - sort the array in numerically or alphabetically

slice() - slice(start, end) returns selected elements into a new array. the start is included, but the end isn't included

reduce() - method reduces the array to a single value (left to right)

 

 

 

 

 

 

Solution 2

const arr = [1, 2, 3, 4, 5]

function miniMaxSum(arr) {
    let reducer = (accumulator, current) => accumulator + current;
    let min = Math.min(...arr);
    let max = Math.max(...arr);
    let dataMax = arr.filter(v => v !== min);
    let dataMin = arr.filter(v => v !== max);

    console.log(dataMin.reduce(reducer) + " " + dataMax.reduce(reducer));
}

miniMaxSum(arr); //10 14

 

처음 solution과 다르게 min 과 max value를 먼저 구하고 계산에 들어갔다. 

 

 

 

 

 

 

Reference

https://www.hackerrank.com/challenges/mini-max-sum/problem

Mini-Max Sum | HackerRank

https://www.w3schools.com/jsref/jsref_obj_array.asp

JavaScript Array Reference

www.javascripttutorial.net/javascript-array-filter/

JavaScript Array Filter: Filtering Array Elements Based on a Test Function