Provjerite može li se iz zadanog niza formirati aritmetička progresija
Isprobajte na GfG Practice 
Izlaz
Izlaz
S obzirom na niz n cijeli brojevi. Zadatak je provjeriti može li se od svih zadanih elemenata sastaviti aritmetička progresija. Ako je moguće ispišite 'Da' inače ispišite 'Ne'.
Primjeri:
unos: arr[] = {0 12 4 8}
Izlaz: Da
Preuredite dani niz kao {0 4 8 12} koji tvori aritmetičku progresiju.
unos: arr[] = {12 40 11 20}
Izlaz: Ne
Korištenje sortiranja - O(n Log n) Vrijeme
Ideja je sortirati dani niz. Nakon sortiranja provjerite jesu li razlike između uzastopnih elemenata jednake ili ne. Ako su sve razlike iste, moguća je aritmetička progresija. Molimo pogledajte - Program za provjeru aritmetičke progresije za implementaciju ovog pristupa.
Korištenje sortiranja brojanjem - O(n) vremena i O(n) prostora
Možemo smanjiti prostor potreban u metodi 3 ako se dani niz može modificirati.
- Pronađite najmanji i drugi najmanji element.
- Pronađite d = drugi_najmanji - najmanji
- Oduzmi najmanji element od svih elemenata.
- Ako dati niz predstavlja AP, svi elementi trebaju biti oblika i*d gdje i varira od 0 do n-1.
- Jedan po jedan sve reducirane elemente podijelite s d. Ako bilo koji element nije djeljiv s d vraća false.
- Sada, ako niz predstavlja AP, to mora biti permutacija brojeva od 0 do n-1. To možemo lako provjeriti koristeći sortiranje brojanjem.
Ispod je implementacija ove metode:
C++ // C++ program to check if a given array // can form arithmetic progression #include using namespace std ; // Checking if array is permutation // of 0 to n-1 using counting sort bool countingsort ( int arr [] int n ) { int count [ n ] = { 0 }; // Counting the frequency for ( int i = 0 ; i < n ; i ++ ) { count [ arr [ i ]] ++ ; } // Check if each frequency is 1 only for ( int i = 0 ; i <= n -1 ; i ++ ) { if ( count [ i ] != 1 ) return false ; } return true ; } // Returns true if a permutation of arr[0..n-1] // can form arithmetic progression bool checkIsAP ( int arr [] int n ) { int smallest = INT_MAX second_smallest = INT_MAX ; for ( int i = 0 ; i < n ; i ++ ) { // Find the smallest and // update second smallest if ( arr [ i ] < smallest ) { second_smallest = smallest ; smallest = arr [ i ]; } // Find second smallest else if ( arr [ i ] != smallest && arr [ i ] < second_smallest ) second_smallest = arr [ i ]; } // Find the difference between smallest and second // smallest int diff = second_smallest - smallest ; for ( int i = 0 ; i < n ; i ++ ) { arr [ i ] = arr [ i ] - smallest ; } for ( int i = 0 ; i < n ; i ++ ) { if ( arr [ i ] % diff != 0 ) { return false ; } else { arr [ i ] = arr [ i ] / diff ; } } // If array represents AP it must be a // permutation of numbers from 0 to n-1. // Check this using counting sort. if ( countingsort ( arr n )) return true ; else return false ; } // Driven Program int main () { int arr [] = { 20 15 5 0 10 }; int n = sizeof ( arr ) / sizeof ( arr [ 0 ]); ( checkIsAP ( arr n )) ? ( cout < < 'Yes' < < endl ) : ( cout < < 'No' < < endl ); return 0 ; // This code is contributed by Pushpesh Raj }
Java // Java program to check if a given array // can form arithmetic progression import java.io.* ; class GFG { // Checking if array is permutation // of 0 to n-1 using counting sort static boolean countingsort ( int arr [] int n ) { int [] count = new int [ n ] ; for ( int i = 0 ; i < n ; i ++ ) count [ i ] = 0 ; // Counting the frequency for ( int i = 0 ; i < n ; i ++ ) { count [ arr [ i ]]++ ; } // Check if each frequency is 1 only for ( int i = 0 ; i <= n - 1 ; i ++ ) { if ( count [ i ] != 1 ) return false ; } return true ; } // Returns true if a permutation of arr[0..n-1] // can form arithmetic progression static boolean checkIsAP ( int arr [] int n ) { int smallest = Integer . MAX_VALUE second_smallest = Integer . MAX_VALUE ; for ( int i = 0 ; i < n ; i ++ ) { // Find the smallest and // update second smallest if ( arr [ i ] < smallest ) { second_smallest = smallest ; smallest = arr [ i ] ; } // Find second smallest else if ( arr [ i ] != smallest && arr [ i ] < second_smallest ) second_smallest = arr [ i ] ; } // Find the difference between smallest and second // smallest int diff = second_smallest - smallest ; for ( int i = 0 ; i < n ; i ++ ) { arr [ i ] = arr [ i ] - smallest ; } for ( int i = 0 ; i < n ; i ++ ) { if ( arr [ i ] % diff != 0 ) { return false ; } else { arr [ i ] = arr [ i ]/ diff ; } } // If array represents AP it must be a // permutation of numbers from 0 to n-1. // Check this using counting sort. if ( countingsort ( arr n )) return true ; else return false ; } // Driven Program public static void main ( String [] args ) { int arr [] = { 20 15 5 0 10 }; int n = arr . length ; if ( checkIsAP ( arr n )) System . out . println ( 'Yes' ); else System . out . println ( 'No' ); } } // This code is contributed by Utkarsh
Python # Python program to check if a given array # can form arithmetic progression import sys # Checking if array is permutation # of 0 to n-1 using counting sort def countingsort ( arr n ): count = [ 0 ] * n ; # Counting the frequency for i in range ( 0 n ): count [ arr [ i ]] += 1 ; # Check if each frequency is 1 only for i in range ( 0 n - 1 ): if ( count [ i ] != 1 ): return False ; return True ; # Returns true if a permutation of arr[0..n-1] # can form arithmetic progression def checkIsAP ( arr n ): smallest = sys . maxsize ; second_smallest = sys . maxsize ; for i in range ( 0 n ): # Find the smallest and # update second smallest if ( arr [ i ] < smallest ) : second_smallest = smallest ; smallest = arr [ i ]; # Find second smallest elif ( arr [ i ] != smallest and arr [ i ] < second_smallest ): second_smallest = arr [ i ]; # Find the difference between smallest and second # smallest diff = second_smallest - smallest ; for i in range ( 0 n ): arr [ i ] = arr [ i ] - smallest ; for i in range ( 0 n ): if ( arr [ i ] % diff != 0 ): return False ; else : arr [ i ] = ( int )( arr [ i ] / diff ); # If array represents AP it must be a # permutation of numbers from 0 to n-1. # Check this using counting sort. if ( countingsort ( arr n )): return True ; else : return False ; # Driven Program arr = [ 20 15 5 0 10 ]; n = len ( arr ); if ( checkIsAP ( arr n )): print ( 'Yes' ); else : print ( 'NO' ); # This code is contributed by ratiagrawal.
C# using System ; class GFG { // Checking if array is permutation // of 0 to n-1 using counting sort static bool CountingSort ( int [] arr int n ) { // Counting the frequency int [] count = new int [ n ]; for ( int i = 0 ; i < n ; i ++ ) { count [ arr [ i ]] ++ ; } // Check if each frequency is 1 only for ( int i = 0 ; i <= n - 1 ; i ++ ) { if ( count [ i ] != 1 ) { return false ; } } return true ; } // Returns true if a permutation of arr[0..n-1] // can form arithmetic progression static bool CheckIsAP ( int [] arr int n ) { // Find the smallest and // update second smallest int smallest = int . MaxValue ; int secondSmallest = int . MaxValue ; for ( int i = 0 ; i < n ; i ++ ) { if ( arr [ i ] < smallest ) { secondSmallest = smallest ; smallest = arr [ i ]; } else if ( arr [ i ] != smallest && arr [ i ] < secondSmallest ) { secondSmallest = arr [ i ]; } } int diff = secondSmallest - smallest ; for ( int i = 0 ; i < n ; i ++ ) { arr [ i ] = arr [ i ] - smallest ; } for ( int i = 0 ; i < n ; i ++ ) { if ( arr [ i ] % diff != 0 ) { return false ; } else { arr [ i ] = arr [ i ] / diff ; } } // If array represents AP it must be a // permutation of numbers from 0 to n-1. // Check this using counting sort. if ( CountingSort ( arr n )) { return true ; } else { return false ; } } // Driven Program static void Main ( string [] args ) { int [] arr = new int [] { 20 15 5 0 10 }; int n = arr . Length ; Console . WriteLine ( CheckIsAP ( arr n ) ? 'Yes' : 'No' ); } }
JavaScript // Javascript program to check if a given array // can form arithmetic progression // Checking if array is permutation // of 0 to n-1 using counting sort function countingsort ( arr n ) { let count = new Array ( n ). fill ( 0 ); // Counting the frequency for ( let i = 0 ; i < n ; i ++ ) { count [ arr [ i ]] ++ ; } // Check if each frequency is 1 only for ( let i = 0 ; i <= n - 1 ; i ++ ) { if ( count [ i ] != 1 ) return false ; } return true ; } // Returns true if a permutation of arr[0..n-1] // can form arithmetic progression function checkIsAP ( arr n ) { let smallest = Number . MAX_SAFE_INTEGER second_smallest = Number . MAX_SAFE_INTEGER ; for ( let i = 0 ; i < n ; i ++ ) { // Find the smallest and // update second smallest if ( arr [ i ] < smallest ) { second_smallest = smallest ; smallest = arr [ i ]; } // Find second smallest else if ( arr [ i ] != smallest && arr [ i ] < second_smallest ) second_smallest = arr [ i ]; } // Find the difference between smallest and second // smallest let diff = second_smallest - smallest ; for ( let i = 0 ; i < n ; i ++ ) { arr [ i ] = arr [ i ] - smallest ; } for ( let i = 0 ; i < n ; i ++ ) { if ( arr [ i ] % diff != 0 ) { return false ; } else { arr [ i ] = arr [ i ] / diff ; } } // If array represents AP it must be a // permutation of numbers from 0 to n-1. // Check this using counting sort. if ( countingsort ( arr n )) return true ; else return false ; } // Driven Program let arr = [ 20 15 5 0 10 ]; let n = arr . length ; ( checkIsAP ( arr n )) ? ( console . log ( 'Yesn' )) : ( console . log ( 'Non' )); // // This code was contributed by poojaagrawal2.
Izlaz
Yes
Vremenska složenost - O(n)
Pomoćni prostor - O(n)
Raspršivanje s jednim prolazom - O(n) vremena i O(n) prostora
Osnovna ideja je pronaći zajedničku razliku AP-a pronalaženjem maksimalnog i minimalnog elementa niza. Nakon toga počnite od maksimalne vrijednosti i nastavite smanjivati vrijednost za uobičajenu razliku uz provjeru je li ta nova vrijednost prisutna u hashmapu ili ne. Ako u bilo kojem trenutku vrijednost nije prisutna u hashsetu, prekinite petlju. Idealna situacija nakon prekida petlje je da je svih n elemenata pokriveno i ako je tako, onda vrati true inače vrati false.
C++ // C++ program for above approach #include using namespace std ; bool checkIsAP ( int arr [] int n ) { unordered_set < int > st ; int maxi = INT_MIN ; int mini = INT_MAX ; for ( int i = 0 ; i < n ; i ++ ) { maxi = max ( arr [ i ] maxi ); mini = min ( arr [ i ] mini ); st . insert ( arr [ i ]); } // FINDING THE COMMON DIFFERENCE int diff = ( maxi - mini ) / ( n - 1 ); int count = 0 ; // CHECK TERMS OF AP PRESENT IN THE HASHSET while ( st . find ( maxi ) != st . end ()) { count ++ ; maxi = maxi - diff ; } if ( count == n ) return true ; return false ; } // Driver Code int main () { int arr [] = { 0 12 4 8 }; int n = 4 ; cout < < boolalpha < < checkIsAP ( arr n ); return 0 ; } // This code is contributed by Rohit Pradhan
Java /*package whatever //do not write package name here */ import java.io.* ; import java.util.* ; class GFG { public static void main ( String [] args ) { int [] arr = { 0 12 4 8 }; int n = arr . length ; System . out . println ( checkIsAP ( arr n )); } static boolean checkIsAP ( int arr [] int n ) { HashSet < Integer > set = new HashSet < Integer > (); int max = Integer . MIN_VALUE ; int min = Integer . MAX_VALUE ; for ( int i : arr ) { max = Math . max ( i max ); min = Math . min ( i min ); set . add ( i ); } // FINDING THE COMMON DIFFERENCE int diff = ( max - min ) / ( n - 1 ); int count = 0 ; // CHECK IF TERMS OF AP PRESENT IN THE HASHSET while ( set . contains ( max )) { count ++ ; max = max - diff ; } if ( count == arr . length ) return true ; return false ; } }
Python import sys def checkIsAP ( arr n ): Set = set () Max = - sys . maxsize - 1 Min = sys . maxsize for i in arr : Max = max ( i Max ) Min = min ( i Min ) Set . add ( i ) # FINDING THE COMMON DIFFERENCE diff = ( Max - Min ) // ( n - 1 ) count = 0 # CHECK IF TERMS OF AP PRESENT IN THE HASHSET while ( Max in Set ): count += 1 Max = Max - diff if ( count == len ( arr )): return True return False # driver code arr = [ 0 12 4 8 ] n = len ( arr ) print ( checkIsAP ( arr n )) # This code is contributed by shinjanpatra
C# using System ; using System.Collections.Generic ; public class GFG { // C# program for above approach static bool checkIsAP ( int [] arr int n ) { HashSet < int > st = new HashSet < int > (); int maxi = int . MinValue ; int mini = int . MaxValue ; for ( int i = 0 ; i < n ; i ++ ) { maxi = Math . Max ( arr [ i ] maxi ); mini = Math . Min ( arr [ i ] mini ); st . Add ( arr [ i ]); } // FINDING THE COMMON DIFFERENCE int diff = ( maxi - mini ) / ( n - 1 ); int count = 0 ; // CHECK IF TERMS OF AP PRESENT IN THE HASHSET while ( st . Contains ( maxi )) { count ++ ; maxi = maxi - diff ; } if ( count == n ) { return true ; } return false ; } // Driver Code internal static void Main () { int [] arr = { 0 12 4 8 }; int n = 4 ; Console . Write ( checkIsAP ( arr n )); } // This code is contributed by Aarti_Rathi }
JavaScript function checkIsAP ( arr n ){ set = new Set () let Max = Number . MIN_VALUE let Min = Number . MAX_VALUE for ( let i of arr ){ Max = Math . max ( i Max ) Min = Math . min ( i Min ) set . add ( i ) } // FINDING THE COMMON DIFFERENCE let diff = Math . floor (( Max - Min ) / ( n - 1 )) let count = 0 // CHECK IF TERMS OF AP PRESENT IN THE HASHSET while ( set . has ( Max )){ count += 1 Max = Max - diff } if ( count == arr . length ) return true return false } // driver code let arr = [ 0 12 4 8 ] let n = arr . length console . log ( checkIsAP ( arr n ))
Izlaz
trueNapravi kviz
