Duoti du sveikieji skaičiai, užduotis yra rasti visų bendrųjų duotųjų skaičių daliklių skaičių?
Pavyzdžiai:
Input : a = 12 b = 24 Output: 6 // all common divisors are 1 2 3 // 4 6 and 12 Input : a = 3 b = 17 Output: 1 // all common divisors are 1 Input : a = 20 b = 36 Output: 3 // all common divisors are 1 2 4Recommended Practice Bendrieji dalikliai Išbandykite!
Rekomenduojama kreiptis visi duoto skaičiaus dalikliai kaip būtina šio straipsnio sąlyga.
Naivus sprendimas
Paprastas sprendimas yra pirmiausia surasti visus pirmojo skaičiaus daliklius ir išsaugoti juos masyve arba maišoje. Tada suraskite bendruosius antrojo skaičiaus daliklius ir išsaugokite juos. Galiausiai atspausdinkite bendrus dviejų saugomų masyvų arba maišos elementus. Svarbiausia, kad daliklio pirminių koeficientų galių dydis būtų lygus dviejų pirminių koeficientų a ir b minimaliai galiai.
- Raskite pagrindinius naudojimo veiksnius pirminis faktorizavimas .
- Raskite kiekvieno pirminio koeficiento skaičių a ir laikykite jį Hashmap.
- Pirminis faktorius b naudojant skirtingus pirminius veiksnius a .
- Tada bendras daliklių skaičius būtų lygus sandaugai (skaičiuoti + 1)
kiekvieno faktoriaus. - Tai suteikia visų daliklių skaičių a ir b . C++
// C++ implementation of program #include using namespace std; // Map to store the count of each // prime factor of a map<int int> ma; // Function that calculate the count of // each prime factor of a number void primeFactorize(int a) { for(int i = 2; i * i <= a; i += 2) { int cnt = 0; while (a % i == 0) { cnt++; a /= i; } ma[i] = cnt; } if (a > 1) { ma[a] = 1; } } // Function to calculate all common // divisors of two given numbers // a b --> input integer numbers int commDiv(int a int b) { // Find count of each prime factor of a primeFactorize(a); // stores number of common divisors int res = 1; // Find the count of prime factors // of b using distinct prime factors of a for(auto m = ma.begin(); m != ma.end(); m++) { int cnt = 0; int key = m->first; int value = m->second; while (b % key == 0) { b /= key; cnt++; } // Prime factor of common divisor // has minimum cnt of both a and b res *= (min(cnt value) + 1); } return res; } // Driver code int main() { int a = 12 b = 24; cout << commDiv(a b) << endl; return 0; } // This code is contributed by divyeshrabadiya07
Java // Java implementation of program import java.util.*; import java.io.*; class GFG { // map to store the count of each prime factor of a static HashMap<Integer Integer> ma = new HashMap<>(); // method that calculate the count of // each prime factor of a number static void primeFactorize(int a) { for (int i = 2; i * i <= a; i += 2) { int cnt = 0; while (a % i == 0) { cnt++; a /= i; } ma.put(i cnt); } if (a > 1) ma.put(a 1); } // method to calculate all common divisors // of two given numbers // a b --> input integer numbers static int commDiv(int a int b) { // Find count of each prime factor of a primeFactorize(a); // stores number of common divisors int res = 1; // Find the count of prime factors of b using // distinct prime factors of a for (Map.Entry<Integer Integer> m : ma.entrySet()) { int cnt = 0; int key = m.getKey(); int value = m.getValue(); while (b % key == 0) { b /= key; cnt++; } // prime factor of common divisor // has minimum cnt of both a and b res *= (Math.min(cnt value) + 1); } return res; } // Driver method public static void main(String args[]) { int a = 12 b = 24; System.out.println(commDiv(a b)); } }
Python3 # Python3 implementation of program import math # Map to store the count of each # prime factor of a ma = {} # Function that calculate the count of # each prime factor of a number def primeFactorize(a): sqt = int(math.sqrt(a)) for i in range(2 sqt 2): cnt = 0 while (a % i == 0): cnt += 1 a /= i ma[i] = cnt if (a > 1): ma[a] = 1 # Function to calculate all common # divisors of two given numbers # a b --> input integer numbers def commDiv(a b): # Find count of each prime factor of a primeFactorize(a) # stores number of common divisors res = 1 # Find the count of prime factors # of b using distinct prime factors of a for key value in ma.items(): cnt = 0 while (b % key == 0): b /= key cnt += 1 # Prime factor of common divisor # has minimum cnt of both a and b res *= (min(cnt value) + 1) return res # Driver code a = 12 b = 24 print(commDiv(a b)) # This code is contributed by Stream_Cipher
C# // C# implementation of program using System; using System.Collections.Generic; class GFG{ // Map to store the count of each // prime factor of a static Dictionary<int int> ma = new Dictionary<int int>(); // Function that calculate the count of // each prime factor of a number static void primeFactorize(int a) { for(int i = 2; i * i <= a; i += 2) { int cnt = 0; while (a % i == 0) { cnt++; a /= i; } ma.Add(i cnt); } if (a > 1) ma.Add(a 1); } // Function to calculate all common // divisors of two given numbers // a b --> input integer numbers static int commDiv(int a int b) { // Find count of each prime factor of a primeFactorize(a); // Stores number of common divisors int res = 1; // Find the count of prime factors // of b using distinct prime factors of a foreach(KeyValuePair<int int> m in ma) { int cnt = 0; int key = m.Key; int value = m.Value; while (b % key == 0) { b /= key; cnt++; } // Prime factor of common divisor // has minimum cnt of both a and b res *= (Math.Min(cnt value) + 1); } return res; } // Driver code static void Main() { int a = 12 b = 24; Console.WriteLine(commDiv(a b)); } } // This code is contributed by divyesh072019
JavaScript <script> // JavaScript implementation of program // Map to store the count of each // prime factor of a let ma = new Map(); // Function that calculate the count of // each prime factor of a number function primeFactorize(a) { for(let i = 2; i * i <= a; i += 2) { let cnt = 0; while (a % i == 0) { cnt++; a = parseInt(a / i 10); } ma.set(i cnt); } if (a > 1) { ma.set(a 1); } } // Function to calculate all common // divisors of two given numbers // a b --> input integer numbers function commDiv(ab) { // Find count of each prime factor of a primeFactorize(a); // stores number of common divisors let res = 1; // Find the count of prime factors // of b using distinct prime factors of a ma.forEach((valueskeys)=>{ let cnt = 0; let key = keys; let value = values; while (b % key == 0) { b = parseInt(b / key 10); cnt++; } // Prime factor of common divisor // has minimum cnt of both a and b res *= (Math.min(cnt value) + 1); }) return res; } // Driver code let a = 12 b = 24; document.write(commDiv(a b)); </script>
Išvestis:
6
Laiko sudėtingumas : O(?n log n)
Pagalbinė erdvė: O(n)
Efektyvus sprendimas -
Geresnis sprendimas yra apskaičiuoti didžiausias bendras daliklis (gcd) duotų dviejų skaičių ir tada suskaičiuokite to gcd daliklius.
// C++ implementation of program #include using namespace std; // Function to calculate gcd of two numbers int gcd(int a int b) { if (a == 0) return b; return gcd(b % a a); } // Function to calculate all common divisors // of two given numbers // a b --> input integer numbers int commDiv(int a int b) { // find gcd of a b int n = gcd(a b); // Count divisors of n. int result = 0; for (int i = 1; i <= sqrt(n); i++) { // if 'i' is factor of n if (n % i == 0) { // check if divisors are equal if (n / i == i) result += 1; else result += 2; } } return result; } // Driver program to run the case int main() { int a = 12 b = 24; cout << commDiv(a b); return 0; }
Java // Java implementation of program class Test { // method to calculate gcd of two numbers static int gcd(int a int b) { if (a == 0) return b; return gcd(b % a a); } // method to calculate all common divisors // of two given numbers // a b --> input integer numbers static int commDiv(int a int b) { // find gcd of a b int n = gcd(a b); // Count divisors of n. int result = 0; for (int i = 1; i <= Math.sqrt(n); i++) { // if 'i' is factor of n if (n % i == 0) { // check if divisors are equal if (n / i == i) result += 1; else result += 2; } } return result; } // Driver method public static void main(String args[]) { int a = 12 b = 24; System.out.println(commDiv(a b)); } }
Python3 # Python implementation of program from math import sqrt # Function to calculate gcd of two numbers def gcd(a b): if a == 0: return b return gcd(b % a a) # Function to calculate all common divisors # of two given numbers # a b --> input integer numbers def commDiv(a b): # find GCD of a b n = gcd(a b) # Count divisors of n result = 0 for i in range(1int(sqrt(n))+1): # if i is a factor of n if n % i == 0: # check if divisors are equal if n/i == i: result += 1 else: result += 2 return result # Driver program to run the case if __name__ == '__main__': a = 12 b = 24; print(commDiv(a b))
C# // C# implementation of program using System; class GFG { // method to calculate gcd // of two numbers static int gcd(int a int b) { if (a == 0) return b; return gcd(b % a a); } // method to calculate all // common divisors of two // given numbers a b --> // input integer numbers static int commDiv(int a int b) { // find gcd of a b int n = gcd(a b); // Count divisors of n. int result = 0; for (int i = 1; i <= Math.Sqrt(n); i++) { // if 'i' is factor of n if (n % i == 0) { // check if divisors are equal if (n / i == i) result += 1; else result += 2; } } return result; } // Driver method public static void Main(String[] args) { int a = 12 b = 24; Console.Write(commDiv(a b)); } } // This code contributed by parashar.
PHP // PHP implementation of program // Function to calculate // gcd of two numbers function gcd($a $b) { if ($a == 0) return $b; return gcd($b % $a $a); } // Function to calculate all common // divisors of two given numbers // a b --> input integer numbers function commDiv($a $b) { // find gcd of a b $n = gcd($a $b); // Count divisors of n. $result = 0; for ($i = 1; $i <= sqrt($n); $i++) { // if 'i' is factor of n if ($n % $i == 0) { // check if divisors // are equal if ($n / $i == $i) $result += 1; else $result += 2; } } return $result; } // Driver Code $a = 12; $b = 24; echo(commDiv($a $b)); // This code is contributed by Ajit. ?> JavaScript <script> // Javascript implementation of program // Function to calculate gcd of two numbers function gcd(a b) { if (a == 0) return b; return gcd(b % a a); } // Function to calculate all common divisors // of two given numbers // a b --> input integer numbers function commDiv(a b) { // find gcd of a b let n = gcd(a b); // Count divisors of n. let result = 0; for (let i = 1; i <= Math.sqrt(n); i++) { // if 'i' is factor of n if (n % i == 0) { // check if divisors are equal if (n / i == i) result += 1; else result += 2; } } return result; } let a = 12 b = 24; document.write(commDiv(a b)); </script>
Išvestis:
6
Laiko sudėtingumas: O (n1/2) kur n yra dviejų skaičių gcd.
Pagalbinė erdvė: O(1)
Kitas požiūris:
1. Apibrėžkite funkciją „gcd“, kuri paima du sveikuosius skaičius „a“ ir „b“ ir grąžina jų didžiausią bendrąjį daliklį (GCD), naudojant Euklido algoritmą.
2. Apibrėžkite funkciją „count_common_divisors“, kuri paima du sveikuosius skaičius „a“ ir „b“ ir suskaičiuoja bendrų „a“ ir „b“ daliklių skaičių, naudodama jų GCD.
3. Apskaičiuokite „a“ ir „b“ GCD naudodami funkciją „gcd“.
4. Inicijuokite skaitiklį „skaičiuoti“ iki 0.
5. Pereikite per visus galimus „a“ ir „b“ GCD daliklius nuo 1 iki GCD kvadratinės šaknies.
6. Jei srovės daliklis padalija GCD tolygiai, padidinkite skaitiklį 2 (nes ir 'a', ir 'b' dalijasi iš daliklio).
7. Jei dabartinio daliklio kvadratas yra lygus GCD, sumažinkite skaitiklį 1 (nes mes jau vieną kartą suskaičiavome šį daliklį).
8. Grąžinkite galutinį bendrųjų daliklių skaičių.
9. Pagrindinėje funkcijoje apibrėžkite du sveikuosius skaičius „a“ ir „b“ ir iškvieskite funkciją „count_common_divisors“ su šiais sveikaisiais skaičiais.
10. Išspausdinkite bendrųjų „a“ ir „b“ daliklių skaičių naudodami printf funkciją.
#include int gcd(int a int b) { if(b == 0) { return a; } return gcd(b a % b); } int count_common_divisors(int a int b) { int gcd_ab = gcd(a b); int count = 0; for(int i = 1; i * i <= gcd_ab; i++) { if(gcd_ab % i == 0) { count += 2; if(i * i == gcd_ab) { count--; } } } return count; } int main() { int a = 12; int b = 18; int common_divisors = count_common_divisors(a b); printf('The number of common divisors of %d and %d is %d.n' a b common_divisors); return 0; }
C++ #include using namespace std; int gcd(int a int b) { if(b == 0) { return a; } return gcd(b a % b); } int count_common_divisors(int a int b) { int gcd_ab = gcd(a b); int count = 0; for(int i = 1; i * i <= gcd_ab; i++) { if(gcd_ab % i == 0) { count += 2; if(i * i == gcd_ab) { count--; } } } return count; } int main() { int a = 12; int b = 18; int common_divisors = count_common_divisors(a b); cout<<'The number of common divisors of '<<a<<' and '<<b<<' is '<<common_divisors<<'.'<<endl; return 0; }
Java import java.util.*; public class Main { public static int gcd(int a int b) { if(b == 0) { return a; } return gcd(b a % b); } public static int countCommonDivisors(int a int b) { int gcd_ab = gcd(a b); int count = 0; for(int i = 1; i * i <= gcd_ab; i++) { if(gcd_ab % i == 0) { count += 2; if(i * i == gcd_ab) { count--; } } } return count; } public static void main(String[] args) { int a = 12; int b = 18; int commonDivisors = countCommonDivisors(a b); System.out.println('The number of common divisors of ' + a + ' and ' + b + ' is ' + commonDivisors + '.'); } }
Python3 import math def gcd(a b): if b == 0: return a return gcd(b a % b) def count_common_divisors(a b): gcd_ab = gcd(a b) count = 0 for i in range(1 int(math.sqrt(gcd_ab)) + 1): if gcd_ab % i == 0: count += 2 if i * i == gcd_ab: count -= 1 return count a = 12 b = 18 common_divisors = count_common_divisors(a b) print('The number of common divisors of' a 'and' b 'is' common_divisors '.') # This code is contributed by Prajwal Kandekar
C# using System; public class MainClass { public static int GCD(int a int b) { if (b == 0) { return a; } return GCD(b a % b); } public static int CountCommonDivisors(int a int b) { int gcd_ab = GCD(a b); int count = 0; for (int i = 1; i * i <= gcd_ab; i++) { if (gcd_ab % i == 0) { count += 2; if (i * i == gcd_ab) { count--; } } } return count; } public static void Main() { int a = 12; int b = 18; int commonDivisors = CountCommonDivisors(a b); Console.WriteLine('The number of common divisors of {0} and {1} is {2}.' a b commonDivisors); } }
JavaScript // Function to calculate the greatest common divisor of // two integers a and b using the Euclidean algorithm function gcd(a b) { if(b === 0) { return a; } return gcd(b a % b); } // Function to count the number of common divisors of two integers a and b function count_common_divisors(a b) { let gcd_ab = gcd(a b); let count = 0; for(let i = 1; i * i <= gcd_ab; i++) { if(gcd_ab % i === 0) { count += 2; if(i * i === gcd_ab) { count--; } } } return count; } let a = 12; let b = 18; let common_divisors = count_common_divisors(a b); console.log(`The number of common divisors of ${a} and ${b} is ${common_divisors}.`);
Išvestis
The number of common divisors of 12 and 18 is 4.
Funkcijos gcd() laiko sudėtingumas yra O(log(min(a b))), nes ji naudoja Euklido algoritmą, kuris ima logaritminį laiką mažesniojo iš dviejų skaičių atžvilgiu.
Funkcijos count_common_divisors() laiko sudėtingumas yra O(sqrt(gcd(a b))), nes ji kartojasi iki dviejų skaičių gcd kvadratinės šaknies.
Abiejų funkcijų sudėtingumas yra O(1), nes jos naudoja tik pastovų atminties kiekį, nepaisant įvesties dydžio.