Brush problem-cc150-java Realize __java

Welcome to visit the blog CC150

Determines whether all characters of a string are all different. Method One: The method of character comparison. Time complexity: O (n2) O (n^2).

Import java.util.*;

public class Different {public
    boolean checkdifferent (String inistring) {
        //write code here
        if (inistring.l Ength () >256) return
            false;
        for (int i=0; I<inistring.length ()-1; i++) {for
            (int j=i+1; j<inistring.length (); j + +) {
                if (inistring.c Harat (i) = = Inistring.charat (j)) return
                    false
            ;
        }
        return true;
    }

Method Two:

Import java.util.*;

public class Different {public
    boolean checkdifferent (String inistring) {
        //write code here
        if (inistring.l Ength () >256) return
            false;
        boolean[] Char_set = new boolean[256];
        for (int i=0; i<inistring.length (); i++) {
            char val = Inistring.charat (i);
            if ((Val < 0) | | (val > 255))    Check the input return
                false;
            if (Char_set[val]) return
                false;
            Char_set[val] = true;
        }
        return true;
    }

1.2 Original string Flip

Flips a given string (you can use a single procedure variable).

Using array to implement

Import java.util.*;

public class Reverse {public
    string reversestring (String inistring) {
        //write code here
        char[] Strarray = in Istring.tochararray ();
        int low = 0, high = inistring.length ()-1;
        while (Low < high) {
            char tmp = Strarray[low];
            Strarray[low] = Strarray[high];
            Strarray[high] = tmp;
            low++;
            high--;
        }
        String tmpstring = new string (strarray);
        Return tmpstring
    }
}

Using StringBuilder

Import java.util.*;

public class Reverse {public
    string reversestring (String inistring) {
        //write code here
        StringBuilder SB = n EW StringBuilder (inistring);
        int low = 0, high = sb.length ()-1;
        While [low < high] {
            char tmp = Sb.charat (low);
            Sb.setcharat (Low, Sb.charat (high));
            Sb.setcharat (High, TMP);
            low++;
            high--;
        }   
        return sb.tostring ();
    }

1.3

Determines whether the character of one of the strings is rearranged and can become another string. Here the big lowercase for different characters, and consider the string key space.

Import java.util.*;

public class Same {public
    boolean Checksam (String Stringa, String stringb) {
        //optimization-if the length of two strings is unequal, it must not be possible if
        (St Ringa.length ()!= stringb.length ()) return
            false;
        Return Sortmy (Stringa). Equals (Sortmy (STRINGB));

    Public String sortmy (string s) {
        char[] as = S.tochararray ();
        Java.util.Arrays.sort (as);
        return new String (AS);
    }

1.4 Space Replacement

Space substitution

Import java.util.*;

public class Replacement {public
    string Replacespace (string inistring, int length) {
        return Inistring.replaceall ("", "%20");
    }

1.5 Basic string Compression

Basic string compression

Import java.util.*;

public class Zipper {public
    string zipstring (String inistring) {
        //write code-here
        String mystr = "";
        Char last = inistring.charat (0);
        int count = 1;
        for (int i=1; i<inistring.length (); i++) {
            if (Inistring.charat (i) ==last) {
                count++;
            } else {
                mystr + = last + "" + count;
                last = Inistring.charat (i);
                Count = 1;
            }
        }
        MyStr + + "" + count;
        if (Mystr.length () > Inistring.length ()) return
            inistring;
        else {return
            mystr;
        }
    }
}

1.6D

1.4D

1.3D

1.4D

1.3D

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