Skriv ut første n tall med nøyaktig to sett biter
Gitt et tall n skriv først ut n positive heltall med nøyaktig to sett biter i sin binære representasjon.
Eksempler:
Input: n = 3
Output: 3 5 6
The first 3 numbers with two set bits are 3 (0011)
5 (0101) and 6 (0110)
Input: n = 5
Output: 3 5 6 9 10 12
EN Enkel løsning er å vurdere alle positive heltall ett etter ett fra 1. For hvert tall sjekk om det har nøyaktig to sett biter. Hvis et tall har nøyaktig to sett biter, skriv det ut og øke antallet av slike tall.
C++
An Effektiv løsning er å generere slike tall direkte. Hvis vi tydelig observerer tallene, kan vi omskrive dem som gitt nedenfor pow(21)+pow(20) pow(22)+pow(20) pow(22)+pow(21) pow(23)+pow(20) pow(23)+pow(21) pow(23)+pow(22) ..........
Alle tall kan genereres i økende rekkefølge i henhold til det høyeste av to sett biter. Ideen er å fikse høyere av to bits én etter én. For gjeldende høyere sett bit vurdere alle lavere biter og skriv ut de dannede tallene.Java// C++ program to print first n numbers // with exactly two set bits #includeusing namespace std ; // Prints first n numbers with two set bits void printTwoSetBitNums ( int n ) { // Initialize higher of two sets bits int x = 1 ; // Keep reducing n for every number // with two set bits. while ( n > 0 ) { // Consider all lower set bits for // current higher set bit int y = 0 ; while ( y < x ) { // Print current number cout < < ( 1 < < x ) + ( 1 < < y ) < < ' ' ; // If we have found n numbers n -- ; if ( n == 0 ) return ; // Consider next lower bit for current // higher bit. y ++ ; } // Increment higher set bit x ++ ; } } // Driver code int main () { printTwoSetBitNums ( 4 ); return 0 ; } Python3// Java program to print first n numbers // with exactly two set bits import java.io.* ; class GFG { // Function to print first n numbers with two set bits static void printTwoSetBitNums ( int n ) { // Initialize higher of two sets bits int x = 1 ; // Keep reducing n for every number // with two set bits while ( n > 0 ) { // Consider all lower set bits for // current higher set bit int y = 0 ; while ( y < x ) { // Print current number System . out . print ((( 1 < < x ) + ( 1 < < y )) + ' ' ); // If we have found n numbers n -- ; if ( n == 0 ) return ; // Consider next lower bit for current // higher bit. y ++ ; } // Increment higher set bit x ++ ; } } // Driver program public static void main ( String [] args ) { int n = 4 ; printTwoSetBitNums ( n ); } } // This code is contributed by Pramod KumarC## Python3 program to print first n # numbers with exactly two set bits # Prints first n numbers # with two set bits def printTwoSetBitNums ( n ) : # Initialize higher of # two sets bits x = 1 # Keep reducing n for every # number with two set bits. while ( n > 0 ) : # Consider all lower set bits # for current higher set bit y = 0 while ( y < x ) : # Print current number print (( 1 < < x ) + ( 1 < < y ) end = ' ' ) # If we have found n numbers n -= 1 if ( n == 0 ) : return # Consider next lower bit # for current higher bit. y += 1 # Increment higher set bit x += 1 # Driver code printTwoSetBitNums ( 4 ) # This code is contributed # by SmithaJavaScript// C# program to print first n numbers // with exactly two set bits using System ; class GFG { // Function to print first n // numbers with two set bits static void printTwoSetBitNums ( int n ) { // Initialize higher of // two sets bits int x = 1 ; // Keep reducing n for every // number with two set bits while ( n > 0 ) { // Consider all lower set bits // for current higher set bit int y = 0 ; while ( y < x ) { // Print current number Console . Write ((( 1 < < x ) + ( 1 < < y )) + ' ' ); // If we have found n numbers n -- ; if ( n == 0 ) return ; // Consider next lower bit // for current higher bit. y ++ ; } // Increment higher set bit x ++ ; } } // Driver program public static void Main () { int n = 4 ; printTwoSetBitNums ( n ); } } // This code is contributed by Anant Agarwal.PHP< script > // Javascript program to print first n numbers // with exactly two set bits // Prints first n numbers with two set bits function printTwoSetBitNums ( n ) { // Initialize higher of two sets bits let x = 1 ; // Keep reducing n for every number // with two set bits. while ( n > 0 ) { // Consider all lower set bits for // current higher set bit let y = 0 ; while ( y < x ) { // Print current number document . write (( 1 < < x ) + ( 1 < < y ) + ' ' ); // If we have found n numbers n -- ; if ( n == 0 ) return ; // Consider next lower bit for current // higher bit. y ++ ; } // Increment higher set bit x ++ ; } } // Driver code printTwoSetBitNums ( 4 ); // This code is contributed by Mayank Tyagi < /script>Utgang:
3 5 6 9
Tidskompleksitet: På)Hjelpeplass: O(1)
Tilnærming #2: Bruk while og bli med
Tilnærmingen er å starte fra heltall 3 og sjekke om antall settbiter i dens binære representasjon er lik 2 eller ikke. Hvis den har nøyaktig 2 sett biter, legg den til listen over tall med 2 sett biter til listen har n elementer.Algoritme
1. Initialiser en tom liste res for å lagre heltallene med nøyaktig to sett biter.
C++
2. Initialiser en heltallsvariabel i til 3.
3. Mens lengden på listen res er mindre enn n, gjør følgende:
en. Sjekk om antall settbiter i den binære representasjonen av i er lik 2 eller ikke ved å bruke count()-metoden til strengen.
b. Hvis antall settbiter er lik 2, legg i til listen res.
c. Øk i med 1.
4. Returner listen res.Java#include#include using namespace std ; int countSetBits ( int num ) { int count = 0 ; while ( num > 0 ) { count += num & 1 ; num >>= 1 ; } return count ; } vector < int > numbersWithTwoSetBits ( int n ) { vector < int > res ; int i = 3 ; while ( res . size () < n ) { if ( countSetBits ( i ) == 2 ) { res . push_back ( i ); } i ++ ; } return res ; } int main () { int n = 3 ; vector < int > result = numbersWithTwoSetBits ( n ); cout < < 'Result: ' ; for ( int i = 0 ; i < result . size (); i ++ ) { cout < < result [ i ] < < ' ' ; } cout < < endl ; return 0 ; } Python3// Java program for the above approach import java.util.ArrayList ; import java.util.List ; public class GFG { // Function to count the number of set bits (binary 1s) // in an integer static int countSetBits ( int num ) { int count = 0 ; while ( num > 0 ) { count += num & 1 ; // Increment count if the last // bit is set (1) num >>= 1 ; // Right shift to check the next bit } return count ; } // Function to generate 'n' numbers with exactly two set // bits in their binary representation static List < Integer > numbersWithTwoSetBits ( int n ) { List < Integer > res = new ArrayList <> (); int i = 3 ; // Start from 3 as the first number with // two set bits while ( res . size () < n ) { if ( countSetBits ( i ) == 2 ) { // Check if the number has exactly // two set bits res . add ( i ); // Add the number to the result list } i ++ ; // Move to the next number } return res ; } public static void main ( String [] args ) { int n = 3 ; // Number of numbers with two set bits to // generate List < Integer > result = numbersWithTwoSetBits ( n ); // Get the generated numbers for ( int num : result ) { System . out . print ( num + ' ' ); // Display the generated numbers } System . out . println (); } } // This code is contributed by Susobhan AkhuliC#def numbersWithTwoSetBits ( n ): res = [] i = 3 while len ( res ) < n : if bin ( i ) . count ( '1' ) == 2 : res . append ( i ) i += 1 return res n = 3 result = numbersWithTwoSetBits ( n ) output_string = ' ' . join ( str ( x ) for x in result ) print ( output_string )JavaScriptusing System ; using System.Collections.Generic ; class Program { // Function to count the number of set bits (binary 1s) in an integer static int CountSetBits ( int num ) { int count = 0 ; while ( num > 0 ) { count += num & 1 ; // Increment count if the last bit is set (1) num >>= 1 ; // Right shift to check the next bit } return count ; } // Function to generate 'n' numbers with exactly two set bits in their binary representation static List < int > NumbersWithTwoSetBits ( int n ) { List < int > res = new List < int > (); int i = 3 ; // Start from 3 as the first number with two set bits while ( res . Count < n ) { if ( CountSetBits ( i ) == 2 ) // Check if the number has exactly two set bits { res . Add ( i ); // Add the number to the result list } i ++ ; // Move to the next number } return res ; } static void Main ( string [] args ) { int n = 3 ; // Number of numbers with two set bits to generate List < int > result = NumbersWithTwoSetBits ( n ); // Get the generated numbers Console . Write ( 'Result: ' ); foreach ( int num in result ) { Console . Write ( num + ' ' ); // Display the generated numbers } Console . WriteLine (); } }
Produksjon3 5 6Tidskompleksitet: O(n log n) hvor n er antall heltall med nøyaktig to sett biter. Dette er fordi vi sjekker antall settbiter i den binære representasjonen av hvert heltall som tar O(log n) tid.
Romkompleksitet: O(n) hvor n er antall heltall med nøyaktig to sett biter. Dette er fordi vi lagrer listen over heltall med to sett biter i minnet.
