Blue Bridge Cup-several routines commonly used in recursion

To find the size of the largest common sub-sequence

 Public classMaximum Common sub-sequence { Public Static voidMain (string[] args) {intK=F ("abc", "ADFEFEXCGFD");    System.out.println (k); }    Private Static intf (String s1, string s2) {if(S1.length () ==0| | S2.length () ==0)return0; if(S1.charat (0) ==s2.charat (0))            returnF (s1.substring (1), s2.substring (1)) +1; Else            returnMath.max (f (s1.substring (1), S2), F (s1,s2.substring (1))); }}

The full array of alphabetic arrays or numbers

/*a b c a C b b a C b c a C B a c a B*/ Public classfull Array { Public Static voidMain (string[] args) {Char[] data= "123456789". ToCharArray (); F (Data,0); }    Private Static voidFChar[] Data,intk) {if(k==data.length) { for(inti = 0; i < data.length; i++) {System.out.print (Data[i]+" ");        } System.out.println (); }                 for(intj = k; J < Data.length; J + +) {            { CharT=DATA[K];d ata[k]=data[j];d ata[j]=t; }//Temptationf (data,k+1);//Recursive{CharT=DATA[K];d ata[k]=data[j];d ata[j]=t; }//Backtracking        }    }}

Super large numbers and rounding of decimals (E,zheigehediguimeiguanxi)

ImportJava.math.BigDecimal;ImportJava.math.BigInteger; Public classlarge numbers and fractions { Public Static voidMain (string[] args) {//a large numberBigInteger bi=biginteger.valueof (1); BigInteger sum=biginteger.valueof (0);  for(inti = 0; I < 64; i++) {sum=sum.add (BI); Bi=bi.multiply (Biginteger.valueof (2));                } System.out.println (sum); //Rounding of decimals        Doubled=1234.546556; BigDecimal BD=NewBigDecimal (d); DoubleD1=bd.setscale (2, bigdecimal.round_half_up). Doublevalue ();    System.out.println (D1); }}

Blue Bridge Cup-several routines commonly used in recursion