Print all Subsequences of String which Start with Vowel and End with Consonant.
Given a string return all possible subsequences which start with vowel and end with consonant. A String is a subsequence of a given String, that is generated by deleting some character of a given string without changing its order.
Examples:
Input : 'abc' Output : ab, ac, abc Input : 'aab' Output : ab, aab
Question Source: Yatra.com Interview Experience | Set 7
Explanation of the Algorithm:
Step 1: Iterate over the entire String
Step 2: check if the ith character for vowel
Step 3: If true iterate the string from the end,
if false move to next iteration
Step 4: check the jth character for consonent
if false move to next iteration
if true perform the following
Step 5: Add the substring starting at index i and
ending at index j to the hastset.
Step 6: Iterate over the substring drop each character
and recur to generate all its subString
C++
// C++ program to generate all the subse-quence// starting with vowel and ending with consonant.#include <bits/stdc++.h>using namespace std; // Set to store all the subsequencesset<string> st; // Utility method to check vowelbool isVowel(char c){ return (c == 'a' or c == 'e' or c == 'i' or c == 'o' or c == 'u');} // Utility method to check consonantbool isConsonant(char c){ return !isVowel(c);} // It computes all the possible substring that// starts with vowel and end with consonentvoid subsequence(string str){ // iterate over the entire string for (int i = 0; i < str.length(); i++) { // test ith character for vowel if (isVowel(str[i])) { // if the ith character is vowel // iterate from end of the string // and check for consonant. for (int j = str.length() - 1; j >= i; j--) { // test jth character for consonant. if (isConsonant(str[j])) { // once we get a consonant add it to // the hashset string str_sub = str.substr(i, j + 1); st.insert(str_sub); // drop each character of the substring // and recur to generate all subsequence // of the substring for (int k = 1; k < str_sub.length() - 1; k++) { string sb = str_sub; sb.erase(sb.begin() + k); subsequence(sb); } } } } }} // Driver Codeint main(){ string s = "xabcef"; subsequence(s); for (auto i : st) cout << i << " "; cout << endl; return 0;} // This code is contributed by// sanjeev2552 |
Java
// Java Program to generate all the subsequence// starting with vowel and ending with consonant.import java.util.HashSet; public class Subsequence { // Set to store all the subsequences static HashSet<String> st = new HashSet<>(); // It computes all the possible substring that // starts with vowel and end with consonent static void subsequence(String str) { // iterate over the entire string for (int i = 0; i < str.length(); i++) { // test ith character for vowel if (isVowel(str.charAt(i))) { // if the ith character is vowel // iterate from end of the string // and check for consonant. for (int j = (str.length() - 1); j >= i; j--) { // test jth character for consonant. if (isConsonant(str.charAt((j)))) { // once we get a consonant add it to // the hashset String str_sub = str.substring(i, j + 1); st.add(str_sub); // drop each character of the substring // and recur to generate all subsequence // of the substring for (int k = 1; k < str_sub.length() - 1; k++) { StringBuffer sb = new StringBuffer(str_sub); sb.deleteCharAt(k); subsequence(sb.toString()); } } } } } } // Utility method to check vowel static boolean isVowel(char c) { return (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u'); } // Utility method to check consonant static boolean isConsonant(char c) { return !isVowel(c); } // Driver code public static void main(String[] args) { String s = "xabcef"; subsequence(s); System.out.println(st); }} |
C#
// C# Program to generate all the subsequence// starting with vowel and ending with consonant.using System;using System.Collections.Generic;using System.Text; class Subsequence{ // Set to store all the subsequences static HashSet<String> st = new HashSet<String>(); // It computes all the possible substring that // starts with vowel and end with consonent static void subsequence(String str) { // iterate over the entire string for (int i = 0; i < str.Length; i++) { // test ith character for vowel if (isVowel(str[i])) { // if the ith character is vowel // iterate from end of the string // and check for consonant. for (int j = (str.Length - 1); j >= i; j--) { // test jth character for consonant. if (isConsonant(str[j])) { // once we get a consonant add it to // the hashset String str_sub = str.Substring(i, j -i + 1); st.Add(str_sub); // drop each character of the substring // and recur to generate all subsequence // of the substring for (int k = 1; k < str_sub.Length - 1; k++) { StringBuilder sb = new StringBuilder(str_sub); sb.Remove(k, 1); subsequence(sb.ToString()); } } } } } } // Utility method to check vowel static bool isVowel(char c) { return (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u'); } // Utility method to check consonant static bool isConsonant(char c) { return !isVowel(c); } // Driver code public static void Main(String[] args) { String s = "xabcef"; subsequence(s); foreach(String str in st) Console.Write(str + ", "); }} // This code is contributed by Rajput-Ji |
Output:
[ef, ab, ac, aef, abc, abf, af, acf, abcef, abcf, acef, abef]
This article is contributed by Sumit Ghosh. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.
In case you wish to attend live classes with industry experts, please refer DSA Live Classes
