Zkontrolujte, zda lze z daného pole vytvořit aritmetickou progresi
Zkuste to na GfG Practice 
Výstup
Výstup
Vzhledem k řadě n celá čísla. Úkolem je ověřit, zda lze pomocí všech daných prvků vytvořit aritmetickou posloupnost. Pokud je to možné, vytiskněte „Ano“, jinak vytiskněte „Ne“.
Příklady:
Vstup: arr[] = {0 12 4 8}
výstup: Ano
Uspořádejte dané pole jako {0 4 8 12}, které tvoří aritmetickou posloupnost.
Vstup: arr[] = {12 40 11 20}
výstup: Žádný
Použití třídění - O(n Log n) Čas
Cílem je seřadit dané pole. Po třídění zkontrolujte, zda jsou rozdíly mezi po sobě jdoucími prvky stejné nebo ne. Pokud jsou všechny rozdíly stejné, je možný aritmetický postup. Podívejte se prosím - Program pro kontrolu aritmetického postupu pro implementaci tohoto přístupu.
Pomocí počítacího třídění - O(n) Čas a O(n) Prostor
Můžeme snížit prostor požadovaný v metodě 3, pokud lze dané pole upravit.
- Najděte nejmenší a druhý nejmenší prvek.
- Najděte d = second_smallest - nejmenší
- Odečtěte nejmenší prvek od všech prvků.
- Nyní, pokud dané pole představuje AP, všechny prvky by měly mít tvar i*d, kde i se mění od 0 do n-1.
- Jeden po druhém rozdělte všechny redukované prvky pomocí d. Pokud některý prvek není dělitelný d, vraťte false.
- Pokud pole představuje AP, musí to být permutace čísel od 0 do n-1. Můžeme to snadno zkontrolovat pomocí počítacího třídění.
Níže je implementace této metody:
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.
Výstup
Yes
Časová složitost – O(n)
Pomocný prostor – O(n)
Hašování s jedním průchodem - O(n) čas a O(n) prostor
Základní myšlenkou je najít společný rozdíl AP zjištěním maximálního a minimálního prvku pole. Poté začněte od maximální hodnoty a pokračujte ve snižování hodnoty o společný rozdíl spolu s kontrolou, zda je tato nová hodnota přítomna v hashmap nebo ne. Pokud v kterémkoli okamžiku hodnota není přítomna v hashsetu, přerušte smyčku. Ideální situace po přerušení smyčky je, že bylo pokryto všech n prvků, a pokud ano, vrátí true, jinak vrátí 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 ))
Výstup
trueVytvořit kvíz
