60 lines
1.8 KiB
Java
60 lines
1.8 KiB
Java
/*
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This program will return all the subsequences of the input string in a string array;
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Sample Input:
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abc
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Sample Output:
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"" ( Empty String )
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c
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b
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bc
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a
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ac
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ab
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abc
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*/
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import java.util.Scanner;
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public class ReturnSubsequence {
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/*
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Main function will accept the given string and implement return subsequences function
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*/
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public static void main(String[] args) {
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System.out.println("Enter String: ");
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Scanner s=new Scanner(System.in);
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String givenString=s.next(); //given string
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String[] subsequence=returnSubsequence(givenString); //calling returnSubsequence() function
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System.out.println("Subsequences : ");
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for(int i=0;i<subsequence.length;i++) //print the given array of subsequences
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{
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System.out.println(subsequence[i]);
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}
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}
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/*
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Recursive function to return Subsequences
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*/
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private static String[] returnSubsequence(String givenString) {
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if(givenString.length()==0) // If string is empty we will create an array of size=1 and insert "" (Empty string) in it
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{
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String[] ans=new String[1];
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ans[0]="";
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return ans;
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}
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String[] SmallAns=returnSubsequence(givenString.substring(1)); //recursive call to get subsequences of substring starting from index position=1
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String[] ans=new String[2*SmallAns.length];// Our answer will be an array off string of size=2*SmallAns
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int i=0;
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for (;i<SmallAns.length;i++)
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{
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ans[i]=SmallAns[i]; //Copying all the strings present in SmallAns to ans string array
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}
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for (int k=0;k<SmallAns.length;k++)
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{
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ans[k+SmallAns.length]=givenString.charAt(0)+SmallAns[k]; // Insert character at index=0 of the given substring in front of every string in SmallAns
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}
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return ans;
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}
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}
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