Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Print prime numbers in a given range using C++ STL
It is the program to print prime numbers in a given range.
Algorithms
Begin Declare a user define datatype stl. Declare a vector number to the stl datatype. Declare variable a to the stl datatype. Declare vector Prime_Number to the Boolean datatype. Prime_Number[0] = false. Prime_Number[1] = false. Declare b to the integer datatype. Initialize b = sqrt(a). for (stl pr=2; pr<=b; pr++) if (Prime_Number[pr]) then for (stl i=pr*2; i<=a; i += pr) Prime_Number[i] = false. Declare result to the vector type. for (int i=0;i<a;i++) if (Prime_Number[i]) then result.push_back(i). return result. End Begin Declare function remove_zero() to the Boolean type. Declare i to the stl datatype. Return i = 0. End Begin Declare a vector Number_Range to the stl datatype. Declare First_Num, Last_Num to the stl datatype. Pass them as parameter. Declare two vector s1 and s2 to the stl datatype. Initialize s1 = number(First_Num) to find primes from o to First_Num. Initialize s2 = number(Last_Num) to find primes from o to Last_Num. Declare vector result(Last_Num-First_Num) to the stl datatype. Call set_difference(s2.begin(), s2.end(), s1.begin(), s2.end(), result.begin()) to find set difference of two vectors. Declare an iterator itr to the vector type. Initialize itr = remove_if(result.begin(),result.end(),remove_zero) to remove extra zeros. Call resize (itr-result.begin()) to resize the result. Return result. Declare First_Num, Last_Num to the stl datatype. Initialize First_Num = 20, Last_Num = 50. Declare a vector result to the stl datatype. Initialize result = Number_Range(First_Num,Last_Num). Print "The Prime Numbers from 20 to 50 are: “ for (auto i:result) Print the values of i. End.
Example
#include<bits/stdc++.h>
using namespace std;
typedef unsigned long long int stl;
vector<stl> number(stl a) {
vector<bool> Prime_Number(a+1,true);
Prime_Number[0] = false;
Prime_Number[1] = false;
int b = sqrt(a);
for (stl pr=2; pr<=b; pr++) {
if (Prime_Number[pr]) {
for (stl i=pr*2; i<=a; i += pr)
Prime_Number[i] = false;
}
}
vector<stl> result;
for (int i=0;i<a;i++)
if (Prime_Number[i])
result.push_back(i);
return result;
}
bool remove_zero(stl i) { // Used to remove zeros from a vector
return i == 0;
}
vector<stl> Number_Range(stl First_Num,stl Last_Num) {
vector<stl> s1 = number(First_Num); // find primes from o to First_Num
vector<stl> s2 = number(Last_Num); // find primes from o to Last_Num
vector<stl> result(Last_Num-First_Num);
set_difference(s2.begin(), s2.end(), s1.begin(), s2.end(), result.begin()); // find set //difference of two vectors
vector<stl>::iterator itr = remove_if(result.begin(),result.end(),remove_zero); //remove extra zeros.
result.resize(itr-result.begin());
return result;
}
int main(void) {
stl First_Num = 20, Last_Num = 50;
vector<stl> result = Number_Range(First_Num,Last_Num);
cout<<"The Prime Numbers from "<<First_Num<<" to "<<Last_Num<< " are: ";
for (auto i:result)
cout<<i<<' ';
return 0;
}Output
The Prime Numbers from 20 to 50 are: 23 29 31 37 41 43 47
Updated on: 30-Jul-2019
421 Views
Advertisements