Java large number practice second play

HDU1250 Water Topic Link: http://acm.hdu.edu.cn/showproblem.php?pid=1250

Import Java.util.*;import Java.math.biginteger;public class main{public    static void Main (string[] args) {        int a ;        Scanner in=new Scanner (system.in);        while (In.hasnext ()) {            a=in.nextint ();            Biginteger[] Num=new biginteger[10000];            Num[1]=biginteger.one;            Num[2]=biginteger.one;            Num[3]=biginteger.one;            Num[4]=biginteger.one;            for (int i=5;i<=a;i++) {                                num[i]= (num[i-1]). Add (Num[i-2]). Add (Num[i-3]).            System.out.println (Num[a]);}}    

hdu1297 Recursive solution Topic link http://acm.hdu.edu.cn/showproblem.php?pid=1297

Import Java.util.*;import Java.math.biginteger;public class main{public    static void Main (string[] args) {        Scanner in= New Scanner (system.in);        int A;        Biginteger[] b= new biginteger[1010];        B[1]=biginteger.one;        B[2]=biginteger.valueof (2);        B[3]=biginteger.valueof (4);        B[4]=biginteger.valueof (7);        while (In.hasnext ()) {            a=in.nextint ();            if (a<5)                System.out.println (B[a]);            else{for                (int i=5;i<=a;i++) {                    b[i]=b[i-1].add (B[i-2]). Add (B[i-4]);                }                System.out.println (B[a]);}}}            

hdu1715 Water Topic link http://acm.hdu.edu.cn/showproblem.php?pid=1715

Import Java.util.*;import Java.math.biginteger;public class main{public    static void Main (string[] args) {        Scanner in= New Scanner (system.in);        Biginteger[] b= new biginteger[1010];        B[1]=biginteger.valueof (1);        B[2]=biginteger.valueof (1);        for (int i=3;i<=1000;i++) {            b[i]=b[i-1].add (b[i-2]);        }        int N=in.nextint ();        while (n-->0) {            int text=in.nextint ();            System.out.println (B[text]);}}    

hdu1753 High-precision Decimal summation topic link http://acm.hdu.edu.cn/showproblem.php?pid=1753

Import Java.util.*;import Java.math.bigdecimal;public class main{public    static void Main (string[] args) {        Scanner in= New Scanner (system.in);        BigDecimal A, B;        while (In.hasnext ()) {            a=in.nextbigdecimal ();            B=in.nextbigdecimal ();            BigDecimal C=a.add (b);             String res = C.striptrailingzeros (). toplainstring (); Striptrailingzeros () Removes the excess 0                                                                  //toplainstring (), cancels the scientific notation notation              System.out.println (res);}        }    

Hdu 1865 find a regular topic link: http://acm.hdu.edu.cn/showproblem.php?pid=1865

Import Java.util.*;import java.math.*;p ublic class main{public    static void Main (string[] args) {        Scanner in= new Scanner (system.in);        int A;        String test;        A=in.nextint ();        Biginteger[] num= new biginteger[210];        Num[1]=biginteger.one;        Num[2]=biginteger.valueof (2);        Num[3]=biginteger.valueof (3);        while (a-->0) {            test=in.next ();            int n=test.length ();            if (n<4)                System.out.println (Num[n]);            else            {for                (int i=4;i<=n;i++) {                    num[i]=num[i-1].add (num[i-2]);                }                System.out.println (Num[n]);}}}    

HDU 2100 binary conversion, the method may be cumbersome but also proficient in many Java usages.

Title Link: http://acm.hdu.edu.cn/showproblem.php?pid=2100

Import Java.util.*;import java.math.*;p ublic class main{public static BigInteger mpow (int b) {//self-written exponentiation function bigin        Teger Ans=biginteger.one;        for (int i=0;i<b;i++) {ans=ans.multiply (biginteger.valueof (26));    } return ans;        public static String change (BigInteger num) {char[] line=new char[250];        int cnt=0;            while (Num.compareto (Biginteger.zero)!=0) {BigInteger a=num.mod (biginteger.valueof (26));            Num=num.divide (Biginteger.valueof (26)); Line[cnt++]= (char) (A.intvalue () + ' a '); Convert BigInteger to int} return string.valueof (line);        Converts a character array to String} public static void Main (string[] args) {Scanner in= new Scanner (system.in);            while (In.hasnext ()) {String A, B;            A=in.next ();            B=in.next ();            BigInteger An=biginteger.zero;            System.out.println (a);            SYSTEM.OUT.PRINTLN ((int) A.charat (1)); for (int i=0;i<a.length (); i++) {An=an.add (biginteger.valueof (A.charat (i)-' a '). Multiply (Mpow (a.length ()-i-1));//string            Single character display with Str.charat (i);            } BigInteger Bn=biginteger.zero; for (int i=0;i<b.length (); i++) {Bn=bn.add (biginteger.valueof (B.charat (i)-' A '). Multiply (Mpow (b.length)-i-            1)));            } BigInteger C=an.add (BN);            String Fin=change (c); for (int i=fin.length () -1;i>=0;i--) {if (Fin.charat (i)! = ') ') System.out.print (Fin.charat (i            ));                    } System.out.println (); }    }}

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Java large number practice second play