HackerRank Marc’s Cakewalk Problem Solution

#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
int compare(const void *a,const void *b){
    return *(int *)b -*(int *)a;
}
int main(){
    int n; 
    scanf("%d",&n);
    int *calories = malloc(sizeof(int) * n);
    for(int calories_i = 0; calories_i < n; calories_i++){
       scanf("%d",&calories[calories_i]);
    }
    qsort(calories,n,sizeof(int),compare);
    long long int sum=0;
    for(int i=0;i<n;i++){
        sum+=calories[i]*pow(2,i);
    }
    printf("%lld",sum);
    // your code goes here
    return 0;
}

#include<bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define all(v) v.begin(),v.end()
#define INF 10000000000000LL
#define P system("pause")
#define print(v) for(typeof(v.begin()) itr = v.begin();itr!=v.end();itr++)cout<<*itr<<" "
#define IN freopen("input.txt","r",stdin)
#define OUT freopen("output.txt","w",stdout)
#define IO IN;OUT
typedef long long ll;
using namespace std;
int main()
{
    //IN;
    ll n,sum=0,temp;
    vector<ll> v;
    cin>>n;
    for(ll i=0;i<n;i++)
    {
        cin>>temp;
        v.pb(temp);
    }
    sort(all(v));
    reverse(all(v));
    for(ll i=0;i<n;i++)
    {
        sum += pow(2,i)*v[i];
    }
    cout<<sum;
return 0;
}

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using static System.Math;
using static System.Array;
class Solution {

    static void Main(String[] args) {
        int n = Convert.ToInt32(Console.ReadLine());
        string[] calories_temp = Console.ReadLine().Split(' ');
        int[] calories = Array.ConvertAll(calories_temp,Int32.Parse);
        // your code goes here
        double sum=0;
        calories = calories.OrderByDescending(c => c).ToArray();
        for(int i=0;i<n;i++)
            {
            sum=sum+ (calories[i]*Math.Pow(2,i));            
        }
        Console.WriteLine(sum.ToString());
    }
}

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class A {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni();
		int[] a = na(n);
		Arrays.sort(a);
		long ret = 0;
		for(int v : a){
			ret = ret * 2 + v;
		}
		out.println(ret);
	}
	
	void run() throws Exception
	{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
	}
	
	public static void main(String[] args) throws Exception { new A().run(); }
	
	private byte[] inbuf = new byte[1024];
	public int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}

process.stdin.resume();
process.stdin.setEncoding('ascii');

var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;

process.stdin.on('data', function (data) {
    input_stdin += data;
});

process.stdin.on('end', function () {
    input_stdin_array = input_stdin.split("\n");
    main();    
});

function readLine() {
    return input_stdin_array[input_currentline++];
}

/////////////// ignore above this line ////////////////////

function main() {
    var n = parseInt(readLine());
    calories = readLine().split(' ');
    calories = calories.map(Number);
    // your code goes here
    
    calories.sort((a, b) => b - a);
    
    //console.log(calories)
    
    let count = 0;
    console.log(calories.reduce((sum, el) => {
        return sum + (el * Math.pow(2, count++));
    }, 0))

}

#!/bin/python3

import sys


n = int(input().strip())
calories = list(map(int, input().strip().split(' ')))
calories.sort(reverse = True)
cnt, ans = 0, 0
for c in calories :
    ans += c * 2 ** cnt
    cnt += 1
print(ans)