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Showing posts from May, 2024

most frequent number

  import java . util .* ; /**  * MostFrequentnumber  */ public class MostFrequentnumber {     public static int MostFrequent ( ArrayList < Integer > nums , int key ) {         int [] result = new int [ 100 ];         for ( int i = 0 ; i < nums . size () - 1 ; i ++ ) {             if ( nums . get ( i ) == key ) {                 result [ nums . get ( i + 1 ) - 1 ] ++ ;             }         }         int max = Integer . MIN_VALUE ;         int ans = 0 ;         for ( int i = 0 ; i < 100 ; i ++ ) {             if ( result [ i ] > max ) {                 max = result [ i ];               ...

lonely numbers

  import java . util .* ; public class LonelyNumbers {     public static ArrayList FindLonelyNumbers ( ArrayList < Integer > nums ) {         Collections . sort ( nums );         ArrayList < Integer > result = new ArrayList <>();         for ( int i = 0 ; i < nums . size (); i ++ ) {             if ( i != 0 && ( nums . get ( i - 1 ) == nums . get ( i ) - 1 || nums . get ( i - 1 ) == nums . get ( i ))) {                 continue ;             }             if ( i != nums . size () - 1 && ( nums . get ( i + 1 ) == nums . get ( i ) + 1 || nums . get ( i + 1 ) == nums . get ( i ))) {                 continue ;             }     ...

monotonic arraylist

  import java . util .* ; public class monotonicArrayList {     public static boolean montonic ( ArrayList < Integer > nums ) {         boolean inc = true ;         boolean dec = true ;         for ( int i = 0 ; i < nums . size () - 1 ; i ++ ) {             int j = i + 1 ;             if ( nums . get ( i ) < nums . get ( j )) {                 inc = false ;             } else if ( nums . get ( i ) > nums . get ( j )) {                 dec = false ;             }         }         return inc || dec ;     }     public static void main ( String [] args ) {         ArrayList < Integer ...

unsorted pairsum

  import java . util . ArrayList ; public class unsortedpairsum {     public static void pairsum ( ArrayList < Integer > list , int target ) {         int bp = 0 ;         int n = list . size ();         for ( int i = 0 ; i < list . size (); i ++ ) {             if ( list . get ( i ) > list . get ( i + 1 )) {                 bp = i ;                 break ;             }         }         int lp = bp + 1 ;         int rp = bp ;         while ( lp != rp ) {             if ( list . get ( lp ) + list . get ( rp ) == target ) {                 System . out . println ( "(" + list ...

pairsum(linear)

  import java . util . ArrayList ; public class pairsum2 {     public static void pairsum ( ArrayList < Integer > list , int target ) {         int lp = 0 ;         int rp = list . size () - 1 ;         while ( lp != rp ) {             if ( list . get ( lp ) + list . get ( rp ) == target ) {                 System . out . println ( "(" + list . get ( lp ) + "," + list . get ( rp ) + ")" );             }             if ( list . get ( lp ) + list . get ( rp ) < target ) {                 lp ++ ;             } else {                 rp -- ;             }         }     }   ...

pairsum(brute force)

  import java . util . ArrayList ; public class pairsum1 {     public static void pairsum ( ArrayList < Integer > list , int target ) {         for ( int i = 0 ; i < list . size (); i ++ ) {             for ( int j = 0 ; j < list . size (); j ++ ) {                 if ( list . get ( i ) + list . get ( j ) == target ) {                     System . out . println ( "(" + list . get ( i ) + "," + list . get ( j ) + ")" );                 }             }         }     }     public static void main ( String [] args ) {         ArrayList < Integer > list = new ArrayList <>();         list . add ( 1 );         list ....

Maximum Water stored in two pointer approach

  import java . util . ArrayList ; public class StoreWater2 {     public static void AreaStored ( ArrayList < Integer > height ) {         int maxwater = 0 ;         int lp = 0 ;         int rp = height . size () - 1 ;         while ( lp < rp ) {             int ht = Math . min ( height . get ( lp ), height . get ( rp ));             int width = rp - lp ;             int currWtr = ht * width ;             maxwater = Math . max ( maxwater , currWtr );             if ( height . get ( lp ) < height . get ( rp )) {                 lp ++ ;             } else {                 rp -- ;   ...

Maximum Water Stored

/**  * TrappingWater  */ import java . util .* ; public class StoreWater {     public static void AreaStored ( ArrayList < Integer > height ) {         int maxwater = 0 ;         for ( int i = 0 ; i < height . size (); i ++ ) {             for ( int j = i + 1 ; j < height . size (); j ++ ) {                 int ht = Math . min ( height . get ( i ), height . get ( j ));                 int width = j - i ;                 int currWtr = ht * width ;                 maxwater = Math . max ( maxwater , currWtr );             }         }         System . out . println ( "maximum water stored:" + maxwater );     } ...

multidimensional ArrayLists

  import java . util . ArrayList ; public class multidimensional {     public static void main ( String [] args ) {         ArrayList < ArrayList < Integer >> mainlist = new ArrayList <>();         ArrayList < Integer > list1 = new ArrayList <>();         ArrayList < Integer > list2 = new ArrayList <>();         ArrayList < Integer > list3 = new ArrayList <>();         for ( int i = 1 ; i <= 5 ; i ++ ) {             list1 . add ( i * 1 );             list2 . add ( i * 2 );             list3 . add ( i * 3 );         }         mainlist . add ( list1 );         mainlist . add ( list2 );         mainlist . add ( list3 ); ...

finding the maximum value in an ArrayList

  import java . util . ArrayList ; public class FindingMax {     public static void main ( String [] args ) {         ArrayList < Integer > list = new ArrayList <>();         list . add ( 1 );         list . add ( 3 );         list . add ( 45 );         list . add ( 71 );         list . add ( 18 );         int max = Integer . MIN_VALUE ;         for ( int i = 0 ; i < list . size (); i ++ ) {             // if (list.get(i)>max) {             // max=list.get(i);             // }             max = Math . max ( max , list . get ( i ));         }         System . out . println ( "The Maximum element:" + max );   ...

swapping in an ArrayList

  import java . util . ArrayList ; public class Swap {     public static void main ( String [] args ) {         ArrayList < Integer > list = new ArrayList <>();         list . add ( 1 );         list . add ( 10 );         list . add ( 18 );         list . add ( 7 );         list . add ( 34 );         list . add ( 5 );         System . out . println ( "ArrayList before swapping:" + list );         // SWAP         int temp = list . get ( 2 );         list . set ( 2 , list . get ( 3 ));         list . set ( 3 , temp );         System . out . println ( "ArayList after swapping:" + list );     } }

sorting in an ArrayList

  import java . util . ArrayList ; import java . util . Collections ; public class sorting {     public static void main ( String [] args ) {         ArrayList < Integer > list = new ArrayList <>();         list . add ( 1 );         list . add ( 10 );         list . add ( 18 );         list . add ( 7 );         list . add ( 34 );         list . add ( 5 );         System . out . println ( "ArrayList before sorting:" + list );         Collections . sort ( list );         System . out . println ( "ArrayList after sorting" + list );         //DESCENDING ORDER         Collections . sort ( list , Collections . reverseOrder ());         System . out . println ( "Descending order:" + list );  ...

printing elementst of an ArrayLis in reverse order

  import java . util . ArrayList ; public class PrintReverse {     public static void main ( String [] args ) {         ArrayList < Integer > list = new ArrayList <>();         list . add ( 1 );         list . add ( 2 );         list . add ( 3 );         list . add ( 4 );         list . add ( 5 );         for ( int i = list . size () - 1 ; i >= 0 ; i -- ) {             System . out . print ( list . get ( i ) + " " );         }         System . out . println ();     } }

Array List -operations

  import java . util . ArrayList ; /**  * Operations  */ public class Operations {     public static void main ( String [] args ) {         ArrayList < Integer > list = new ArrayList <>();         // TO ADD ELEMENTS         list . add ( 1 );         list . add ( 2 );         list . add ( 3 );         list . add ( 4 );         list . add ( 5 );         System . out . println ( list );         list . add ( 2 , 10 );         System . out . println ( list );         // TO GET ELEMENT         System . out . println ( list . get ( 0 ));         // TO REMOVE         list . remove ( 2 );         System . out . println ( "ArrayList after deletion" ); ...

knight paths

  public class Knightpaths {     public static void path ( int board [][], int i , int j , int movenumber , int n ) {         if ( i < 0 || j < 0 || i >= n || j >= n ) {             return ;         }         if ( board [ i ][ j ] != 0 ) {             return ;         }         board [ i ][ j ] = movenumber ;         if ( movenumber == n * n - 1 ) {             for ( int x = 0 ; x < board . length ; x ++ ) {                 for ( int y = 0 ; y < board . length ; y ++ ) {                     System . out . print ( board [ x ][ y ] + " " );                 }     ...