Dados L y R. La tarea es encontrar el número en cuya representación binaria todos los bits entre el índice L-th y R-th están activados y el resto de los bits están desactivados. La representación binaria es de 32 bits.
Ejemplos:
Entrada: L = 2, R = 5
Salida: 60
Explicación: La representación binaria es
0..0111100 => 60Entrada: L = 1, R = 3
Salida: 14
Explicación: La representación binaria es
0..01110 => 14
Enfoque ingenuo: el enfoque ingenuo para encontrar el número es iterar de i = L a i = R y calcular la suma de todas las potencias de 2 i .
El siguiente programa ilustra el enfoque ingenuo:
C++
// CPP program to print the integer
// with all the bits set in range L-R
// Naive Approach
#include <bits/stdc++.h>
using namespace std;
// Function to return the integer
// with all the bits set in range L-R
int getInteger(int L, int R)
{
int number = 0;
// iterate from L to R
// and add all powers of 2
for (int i = L; i <= R; i++)
number += pow(2, i);
return number;
}
// Driver Code
int main()
{
int L = 2, R = 5;
cout << getInteger(L, R);
return 0;
}
Java
// Java program to print the
// integer with all the bits
// set in range L-R Naive Approach
import java.io.*;
class GFG
{
// Function to return the
// integer with all the
// bits set in range L-R
static int getInteger(int L,
int R)
{
int number = 0;
// iterate from L to R
// and add all powers of 2
for (int i = L; i <= R; i++)
number += Math.pow(2, i);
return number;
}
// Driver Code
public static void main (String[] args)
{
int L = 2, R = 5;
System.out.println(getInteger(L, R));
}
}
// This code is contributed by anuj_67..
Python3
# Python 3 program to print the integer # with all the bits set in range L-R # Naive Approach from math import pow # Function to return the integer # with all the bits set in range L-R def getInteger(L, R): number = 0 # iterate from L to R # and add all powers of 2 for i in range(L, R + 1, 1): number += pow(2, i) return number # Driver Code if __name__ == '__main__': L = 2 R = 5 print(int(getInteger(L, R))) # This code is contributed by # Surendra_Gangwar
C#
// C# program to print the
// integer with all the bits
// set in range L-R Naive Approach
using System;
class GFG
{
// Function to return the
// integer with all the
// bits set in range L-R
static int getInteger(int L,
int R)
{
int number = 0;
// iterate from L to R
// and add all powers of 2
for (int i = L; i <= R; i++)
number += (int)Math.Pow(2, i);
return number;
}
// Driver Code
public static void Main ()
{
int L = 2, R = 5;
Console.Write(getInteger(L, R));
}
}
// This code is contributed
// by shiv_bhakt.
PHP
<?php
// PHP program to print
// the integer with all
// the bits set in range
// L-R Naive Approach
// Function to return the
// integer with all the
// bits set in range L-R
function getInteger($L, $R)
{
$number = 0;
// iterate from L to R
// and add all powers of 2
for ($i = $L; $i <= $R; $i++)
$number += pow(2, $i);
return $number;
}
// Driver Code
$L = 2;
$R = 5;
echo getInteger($L, $R);
// This code is contributed
// by shiv_bhakt.
?>
Javascript
<script>
// Javascript program to print the integer
// with all the bits set in range L-R
// Naive Approach
// Function to return the integer
// with all the bits set in range L-R
function getInteger(L, R)
{
var number = 0;
// iterate from L to R
// and add all powers of 2
for (var i = L; i <= R; i++)
number += Math.pow(2, i);
return number;
}
// Driver Code
var L = 2, R = 5;
document.write( getInteger(L, R));
</script>
Producción:
60
Un enfoque eficiente es calcular el número con todos los bits (R) configurados desde la derecha y restar el número con todos los bits (L-1) configurados desde la derecha para obtener el número requerido.
1. Calcule el número que tiene todos los bits establecidos de R desde la derecha usando la fórmula a continuación.
(1 << (R+1)) - 1.
2. Reste el número que tiene todos los bits establecidos (L-1) desde la derecha.
(1<<L) - 1
Por lo tanto, calculando ((1<<(R+1))-1)-((1<<L)-1), obtenemos la fórmula final como:
(1<<(R+1))-(1<<L)
El siguiente programa ilustra el enfoque eficiente:
C++
// CPP program to print the integer
// with all the bits set in range L-R
// Efficient Approach
#include <bits/stdc++.h>
using namespace std;
// Function to return the integer
// with all the bits set in range L-R
int setbitsfromLtoR(int L, int R)
{
return (1 << (R + 1)) - (1 << L);
}
// Driver Code
int main()
{
int L = 2, R = 5;
cout << setbitsfromLtoR(L, R);
return 0;
}
Java
// Java program to print
// the integer with all
// the bits set in range
// L-R Efficient Approach
import java.io.*;
class GFG
{
// Function to return the
// integer with all the
// bits set in range L-R
static int setbitsfromLtoR(int L,
int R)
{
return (1 << (R + 1)) -
(1 << L);
}
// Driver Code
public static void main (String[] args)
{
int L = 2, R = 5;
System.out.println(setbitsfromLtoR(L, R));
}
}
// This code is contributed
// by shiv_bhakt.
Python3
# Python3 program to print # the integer with all the # bits set in range L-R # Efficient Approach # Function to return the # integer with all the # bits set in range L-R def setbitsfromLtoR(L, R): return ((1 << (R + 1)) - (1 << L)) # Driver Code L = 2 R = 5 print(setbitsfromLtoR(L, R)) # This code is contributed # by Smita
C#
// C# program to print
// the integer with all
// the bits set in range
// L-R Efficient Approach
using System;
class GFG
{
// Function to return the
// integer with all the
// bits set in range L-R
static int setbitsfromLtoR(int L,
int R)
{
return (1 << (R + 1)) -
(1 << L);
}
// Driver Code
public static void Main ()
{
int L = 2, R = 5;
Console.WriteLine(setbitsfromLtoR(L, R));
}
}
// This code is contributed
// by shiv_bhakt.
PHP
<?php
// PHP program to print
// the integer with all
// the bits set in range
// L-R Efficient Approach
// Function to return the
// integer with all the
// bits set in range L-R
function setbitsfromLtoR($L, $R)
{
return (1 << ($R + 1)) -
(1 << $L);
}
// Driver Code
$L = 2;
$R = 5;
echo setbitsfromLtoR($L, $R);
// This code is contributed
// by shiv_bhakt.
?>
Javascript
<script>
// Javascript program to print the integer
// with all the bits set in range L-R
// Efficient Approach
// Function to return the integer
// with all the bits set in range L-R
function setbitsfromLtoR(L, R)
{
return (1 << (R + 1)) - (1 << L);
}
// Driver Code
var L = 2, R = 5;
document.write( setbitsfromLtoR(L, R));
// This code is contributed by famously.
</script>
Producción:
60
Complejidad de Tiempo : O(1)
Espacio Auxiliar : O(1)
Publicación traducida automáticamente
Artículo escrito por aganjali10 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA