Comptar maneres d'escriure un nombre amb xifres repetides
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#practiceLinkDiv { mostrar: cap !important; } Donada una cadena que conté xifres d'un nombre. El número pot contenir molts dígits continus iguals. La tasca és comptar el nombre de maneres d'escriure el nombre.
Per exemple, considereu 8884441100 es pot escriure simplement com a triple vuit, triple quatre, doble dos i doble zero. També es pot escriure doble vuit vuit quatre doble quatre dos dos doble zero.
Exemples:
Input : num = 100 Output : 2 The number 100 has only 2 possibilities 1) one zero zero 2) one double zero. Input : num = 11112 Output: 8 1 1 1 1 2 11 1 1 2 1 1 11 2 1 11 1 2 11 11 2 1 111 2 111 1 2 1111 2 Input : num = 8884441100 Output: 64 Input : num = 12345 Output: 1 Input : num = 11111 Output: 16Recommended Practice Escriu un nombre Prova-ho!
Aquest és un simple problema de permutació i combinació. Si prenem un exemple de cas de prova donat a la pregunta 11112. La resposta depèn del nombre de possibles subcadenes de 1111. El nombre de possibles subcadenes de '1111' és 2^3 = 8 perquè és el nombre de combinacions de 4 - 1 = 3 separadors '|' entre dos caràcters de la cadena (dígits del nombre representats per la cadena): '1|1|1|1'. Com que les nostres combinacions dependran de si triem un 1 particular i per a '2' només hi haurà una possibilitat 2^0 = 1, de manera que la resposta per a '11112' serà 8*1 = 8.
Per tant, l'enfocament és comptar el dígit continu particular de la cadena i multiplicar 2 ^ (compte-1) amb el resultat anterior.
C++ // C++ program to count number of ways we // can spell a number #include using namespace std ; typedef long long int ll ; // Function to calculate all possible spells of // a number with repeated digits // num --> string which is favourite number ll spellsCount ( string num ) { int n = num . length (); // final count of total possible spells ll result = 1 ; // iterate through complete number for ( int i = 0 ; i < n ; i ++ ) { // count contiguous frequency of particular // digit num[i] int count = 1 ; while ( i < n -1 && num [ i + 1 ] == num [ i ]) { count ++ ; i ++ ; } // Compute 2^(count-1) and multiply with result result = result * pow ( 2 count -1 ); } return result ; } // Driver program to run the case int main () { string num = '11112' ; cout < < spellsCount ( num ); return 0 ; }
Java // Java program to count number of ways we // can spell a number import java.io.* ; class GFG { // Function to calculate all possible // spells of a number with repeated digits // num --> string which is favourite number static long spellsCount ( String num ) { int n = num . length (); // final count of total possible spells long result = 1 ; // iterate through complete number for ( int i = 0 ; i < n ; i ++ ) { // count contiguous frequency of // particular digit num[i] int count = 1 ; while ( i < n - 1 && num . charAt ( i + 1 ) == num . charAt ( i )) { count ++ ; i ++ ; } // Compute 2^(count-1) and multiply // with result result = result * ( long ) Math . pow ( 2 count - 1 ); } return result ; } public static void main ( String [] args ) { String num = '11112' ; System . out . print ( spellsCount ( num )); } } // This code is contributed by Anant Agarwal.
Python3 # Python3 program to count number of # ways we can spell a number # Function to calculate all possible # spells of a number with repeated # digits num --> string which is # favourite number def spellsCount ( num ): n = len ( num ); # final count of total # possible spells result = 1 ; # iterate through complete # number i = 0 ; while ( i < n ): # count contiguous frequency # of particular digit num[i] count = 1 ; while ( i < n - 1 and num [ i + 1 ] == num [ i ]): count += 1 ; i += 1 ; # Compute 2^(count-1) and # multiply with result result = result * int ( pow ( 2 count - 1 )); i += 1 ; return result ; # Driver Code num = '11112' ; print ( spellsCount ( num )); # This code is contributed # by mits
C# // C# program to count number of ways we // can spell a number using System ; class GFG { // Function to calculate all possible // spells of a number with repeated // digits num --> string which is // favourite number static long spellsCount ( String num ) { int n = num . Length ; // final count of total possible // spells long result = 1 ; // iterate through complete number for ( int i = 0 ; i < n ; i ++ ) { // count contiguous frequency of // particular digit num[i] int count = 1 ; while ( i < n - 1 && num [ i + 1 ] == num [ i ]) { count ++ ; i ++ ; } // Compute 2^(count-1) and multiply // with result result = result * ( long ) Math . Pow ( 2 count - 1 ); } return result ; } // Driver code public static void Main () { String num = '11112' ; Console . Write ( spellsCount ( num )); } } // This code is contributed by nitin mittal.
PHP // PHP program to count // number of ways we // can spell a number // Function to calculate // all possible spells of // a number with repeated // digits num --> string // which is favourite number function spellsCount ( $num ) { $n = strlen ( $num ); // final count of total // possible spells $result = 1 ; // iterate through // complete number for ( $i = 0 ; $i < $n ; $i ++ ) { // count contiguous frequency // of particular digit num[i] $count = 1 ; while ( $i < $n - 1 && $num [ $i + 1 ] == $num [ $i ]) { $count ++ ; $i ++ ; } // Compute 2^(count-1) and // multiply with result $result = $result * pow ( 2 $count - 1 ); } return $result ; } // Driver Code $num = '11112' ; echo spellsCount ( $num ); // This code is contributed // by nitin mittal. ?>
JavaScript < script > // Javascript program to count number of // ways we can spell a number // Function to calculate all possible // spells of a number with repeated // digits num --> string which is // favourite number function spellsCount ( num ) { let n = num . length ; // Final count of total possible // spells let result = 1 ; // Iterate through complete number for ( let i = 0 ; i < n ; i ++ ) { // Count contiguous frequency of // particular digit num[i] let count = 1 ; while ( i < n - 1 && num [ i + 1 ] == num [ i ]) { count ++ ; i ++ ; } // Compute 2^(count-1) and multiply // with result result = result * Math . pow ( 2 count - 1 ); } return result ; } // Driver code let num = '11112' ; document . write ( spellsCount ( num )); // This code is contributed by code_hunt < /script>
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8
Complexitat temporal: O(n*log(n))
Espai auxiliar: O(1)
Si teniu un altre enfocament per resoldre aquest problema, compartiu-lo.
