Dada una array de strings arr[] , la tarea es imprimir todas las strings únicas que están presentes en la array dada.
Ejemplos:
Entrada: arr[] = { “geeks”, “geek”, “ab”, “geek” “code”, “karega” }
Salida: geeks ab code karega
Explicación:
La frecuencia de la string “geeks” es 1.
La La frecuencia de la string «geek» es 2.
La frecuencia de la string «ab» es 1.
La frecuencia de la string «code» es 1.
La frecuencia de la string «karega» es 1.
Por lo tanto, la salida requerida es » geeks ab código karega”Entrada: arr[] = { “abcde”, “abcd”, “abcd”, “co” “”, “código” }
Salida: abcde co código
Enfoque ingenuo: el enfoque más simple para resolver este problema es recorrer la array para cada string encontrada, verificar si esa string aparece en la array restante o no. Imprima esas strings que ocurren solo una vez en la array.
Complejidad de Tiempo: O(N 2 * M), donde M es la longitud máxima de la string
Espacio Auxiliar: O(1)
Enfoque eficiente: el enfoque anterior se puede optimizar utilizando Trie . La idea es atravesar la array y para cada i -ésima string en la array, verificar si arr[i] está presente en el Trie o no. Si es cierto, marque arr[i] como elemento de array duplicado. De lo contrario, marque arr[i] como elemento de array único e inserte arr[i] en el trie . Siga los pasos a continuación para resolver el problema:
- Inicialice una array , digamos isUniq[] , para verificar si un elemento de la array es único o no .
- Cree un Trie que tenga un Node raíz, digamos root , para almacenar los caracteres de cada string presente en la array dada.
- Recorra la array usando la variable i y para cada i -ésimo elemento, verifique si arr[i] está presente en el Trie o no. SI se encuentra que es verdadero, entonces actualice isUniq[i] a falso.
- De lo contrario, actualice isUniq[i] a verdadero e inserte arr[i] en Trie.
- Finalmente, recorra la array isUniq[] usando la variable i y para cada i -ésimo elemento, verifique si isUniq[i] es verdadero o no. Si se encuentra que es cierto, imprima arr[i] .
A continuación se muestra la implementación del enfoque anterior:
C++
// C++ program to implement
// the above approach
#include <bits/stdc++.h>
using namespace std;
// Structure of
// a Trie node
struct TrieNode {
// Stores index
// of string
int idx;
// Check if a character is
// present in the string or not
TrieNode* child[26];
// Initialize a TrieNode
TrieNode()
{
// Idx = -1: String is not
// present in TrieNode
idx = -1;
// Initialize all child nodes
// of a TrieNode to NULL
for (int i = 0; i < 26; i++) {
// Update child[i]
child[i] = NULL;
}
}
};
// Function to insert a string into Trie
void Insert(TrieNode* root,
string str, int i)
{
// Stores length of the string
int N = str.length();
// Traverse the string str
for (int i = 0; i < N; i++) {
// If str[i] not present in
// a Trie at current index
if (!root->child[str[i] - 'a']) {
// Create a new node of Trie.
root->child[str[i] - 'a']
= new TrieNode();
}
// Update root
root = root->child[str[i] - 'a'];
}
// Store index of str
// in the TrieNode
root->idx = i;
}
// Function to check if string str present
// in the Trie or not
int SearchString(TrieNode* root, string str)
{
// Stores length of
// the string
int N = str.length();
// Traverse the string
for (int i = 0; i < N; i++) {
// If a character not present
// in Trie at current index
if (!root->child[str[i] - 'a']) {
// Return str as
// unique string
return -1;
}
// Update root
root
= root->child[str[i] - 'a'];
}
// Return index of str
return root->idx;
}
// Utility function to find the unique
// string in array of strings
void UtilUniqStr(vector<string>& arr, int N)
{
// Stores root node of the Trie
TrieNode* root = new TrieNode();
// isUniq[i]: Check if i-th string
// is unique or not
bool isUniq[N];
// Initialize isUniq[] to false
memset(isUniq, false, sizeof(isUniq));
// Insert arr[0] into the Trie
Insert(root, arr[0], 0);
// Mark arr[0] as unique string
isUniq[0] = true;
// Traverse the given array
for (int i = 1; i < N; i++) {
// Stores previous 1st index
// of arr[i] in the array
int idx = SearchString(root,
arr[i]);
// If arr[i] not present
// in the Trie
if (idx == -1) {
// Mark i-th string
// as unique string
isUniq[i] = true;
// Insert arr[i] into Trie
Insert(root, arr[i], i);
}
// If arr[i] already present
// in the Trie
else {
// Mark i-th string as
// duplicate string in Trie
isUniq[idx] = false;
}
}
// Traverse the array
for (int i = 0; i < N; i++) {
// If i-th string is unique,
// then print the string
if (isUniq[i]) {
cout << arr[i] << " ";
}
}
}
// Driver Code
int main()
{
vector<string> arr = { "geeks", "for",
"geek", "ab", "geek",
"for", "code", "karega" };
int N = arr.size();
UtilUniqStr(arr, N);
return 0;
}
Java
// Java program to implement
// the above approach
import java.util.*;
class GFG
{
// Structure of
// a Trie node
static class TrieNode {
// Stores index
// of String
int idx;
// Check if a character is
// present in the String or not
TrieNode []child = new TrieNode[26];
// Initialize a TrieNode
TrieNode()
{
// Idx = -1: String is not
// present in TrieNode
idx = -1;
// Initialize all child nodes
// of a TrieNode to null
for (int i = 0; i < 26; i++) {
// Update child[i]
child[i] = null;
}
}
};
// Function to insert a String into Trie
static void Insert(TrieNode root,
String str, int i)
{
// Stores length of the String
int N = str.length();
// Traverse the String str
for (int j = 0; j < N; j++) {
// If str[i] not present in
// a Trie at current index
if (root.child[str.charAt(j) - 'a']==null) {
// Create a new node of Trie.
root.child[str.charAt(j) - 'a']
= new TrieNode();
}
// Update root
root = root.child[str.charAt(j) - 'a'];
}
// Store index of str
// in the TrieNode
root.idx = i;
}
// Function to check if String str present
// in the Trie or not
static int SearchString(TrieNode root, String str)
{
// Stores length of
// the String
int N = str.length();
// Traverse the String
for (int i = 0; i < N; i++) {
// If a character not present
// in Trie at current index
if (root.child[str.charAt(i) - 'a'] == null) {
// Return str as
// unique String
return -1;
}
// Update root
root
= root.child[str.charAt(i) - 'a'];
}
// Return index of str
return root.idx;
}
// Utility function to find the unique
// String in array of Strings
static void UtilUniqStr(String[] arr, int N)
{
// Stores root node of the Trie
TrieNode root = new TrieNode();
// isUniq[i]: Check if i-th String
// is unique or not
boolean []isUniq = new boolean[N];
// Insert arr[0] into the Trie
Insert(root, arr[0], 0);
// Mark arr[0] as unique String
isUniq[0] = true;
// Traverse the given array
for (int i = 1; i < N; i++) {
// Stores previous 1st index
// of arr[i] in the array
int idx = SearchString(root,
arr[i]);
// If arr[i] not present
// in the Trie
if (idx == -1) {
// Mark i-th String
// as unique String
isUniq[i] = true;
// Insert arr[i] into Trie
Insert(root, arr[i], i);
}
// If arr[i] already present
// in the Trie
else {
// Mark i-th String as
// duplicate String in Trie
isUniq[idx] = false;
}
}
// Traverse the array
for (int i = 0; i < N; i++) {
// If i-th String is unique,
// then print the String
if (isUniq[i]) {
System.out.print(arr[i]+ " ");
}
}
}
// Driver Code
public static void main(String[] args)
{
String[] arr = { "geeks", "for",
"geek", "ab", "geek",
"for", "code", "karega" };
int N = arr.length;
UtilUniqStr(arr, N);
}
}
// This code is contributed by 29AjayKumar
Python3
# Python3 program to implement
# the above approach
root = None
# Structure of
# a Trie node
class TrieNode:
# Stores index
# of string
def __init__(self):
self.idx = -1
self.child = [None]*26
# Function to insert a string into Trie
def Insert(str, i):
global root
# Stores length of the string
N = len(str)
root1 = root
# Traverse the string str
for i in range(N):
# If str[i] not present in
# a Trie at current index
if (not root1.child[ord(str[i]) - ord('a')]):
# Create a new node of Trie.
root1.child[ord(str[i]) - ord('a')] = TrieNode()
# Update root
root1 = root1.child[ord(str[i]) - ord('a')]
# Store index of str
# in the TrieNode
root1.idx = i
return root1
# Function to check if string str present
# in the Trie or not
def SearchString(str):
global root
root1 = root
# Stores length of
# the
N = len(str)
# Traverse the
for i in range(N):
# If a character not present
# in Trie at current index
if (not root1.child[ord(str[i]) - ord('a')]):
# Return str as
# unique
return -1
# Update root
root1 = root1.child[ord(str[i]) - ord('a')]
# Return index of str
return root1.idx
# Utility function to find the unique
# string in array of strings
def UtilUniqStr(arr, N):
global root
# Stores root node of the Trie
root = TrieNode()
d = {}
for i in arr:
d[i] = d.get(i, 0) + 1
# isUniq[i]: Check if i-th string
# is unique or not
isUniq = [False] * N
# Initialize isUniq[] to false
# memset(isUniq, false, sizeof(isUniq));
# Insert arr[0] into the Trie
Insert(arr[0], 0)
# Mark arr[0] as unique string
isUniq[0] = True
# print(root.child[6].child)
# Traverse the given array
for i in range(1, N):
# Stores previous 1st index
# of arr[i] in the array
idx = SearchString(arr[i])
# If arr[i] not present
# in the Trie
if (idx == -1 and d[arr[i]] == 1):
# Mark i-th string
# as unique string
isUniq[i] = True
# Insert arr[i] into Trie
Insert(arr[i], i)
# If arr[i] already present
# in the Trie
else:
# Mark i-th string as
# duplicate string in Trie
isUniq[idx] = False
# Traverse the array
for i in range(N):
# If i-th string is unique,
# then print the string
if (isUniq[i]):
print(arr[i], end = " ")
# Driver Code
if __name__ == '__main__':
arr = ["geeks", "for","geek", "ab", "geek","for", "code", "karega"]
N = len(arr)
UtilUniqStr(arr, N)
# This code is contributed by mohit kumar 29
C#
// C# program to implement
// the above approach
using System;
class GFG
{
// Structure of
// a Trie node
class TrieNode {
// Stores index
// of String
public int idx;
// Check if a character is
// present in the String or not
public TrieNode []child = new TrieNode[26];
// Initialize a TrieNode
public TrieNode()
{
// Idx = -1: String is not
// present in TrieNode
idx = -1;
// Initialize all child nodes
// of a TrieNode to null
for (int i = 0; i < 26; i++) {
// Update child[i]
child[i] = null;
}
}
};
// Function to insert a String into Trie
static void Insert(TrieNode root,
String str, int i)
{
// Stores length of the String
int N = str.Length;
// Traverse the String str
for (int j = 0; j < N; j++) {
// If str[i] not present in
// a Trie at current index
if (root.child[str[j] - 'a'] == null) {
// Create a new node of Trie.
root.child[str[j] - 'a']
= new TrieNode();
}
// Update root
root = root.child[str[j] - 'a'];
}
// Store index of str
// in the TrieNode
root.idx = i;
}
// Function to check if String str present
// in the Trie or not
static int SearchString(TrieNode root, String str)
{
// Stores length of
// the String
int N = str.Length;
// Traverse the String
for (int i = 0; i < N; i++) {
// If a character not present
// in Trie at current index
if (root.child[str[i] - 'a'] == null) {
// Return str as
// unique String
return -1;
}
// Update root
root
= root.child[str[i] - 'a'];
}
// Return index of str
return root.idx;
}
// Utility function to find the unique
// String in array of Strings
static void UtilUniqStr(String[] arr, int N)
{
// Stores root node of the Trie
TrieNode root = new TrieNode();
// isUniq[i]: Check if i-th String
// is unique or not
bool []isUniq = new bool[N];
// Insert arr[0] into the Trie
Insert(root, arr[0], 0);
// Mark arr[0] as unique String
isUniq[0] = true;
// Traverse the given array
for (int i = 1; i < N; i++) {
// Stores previous 1st index
// of arr[i] in the array
int idx = SearchString(root,
arr[i]);
// If arr[i] not present
// in the Trie
if (idx == -1) {
// Mark i-th String
// as unique String
isUniq[i] = true;
// Insert arr[i] into Trie
Insert(root, arr[i], i);
}
// If arr[i] already present
// in the Trie
else {
// Mark i-th String as
// duplicate String in Trie
isUniq[idx] = false;
}
}
// Traverse the array
for (int i = 0; i < N; i++) {
// If i-th String is unique,
// then print the String
if (isUniq[i]) {
Console.Write(arr[i] + " ");
}
}
}
// Driver Code
public static void Main(String[] args)
{
String[] arr = { "geeks", "for",
"geek", "ab", "geek",
"for", "code", "karega" };
int N = arr.Length;
UtilUniqStr(arr, N);
}
}
// This code is contributed by 29AjayKumar
Javascript
<script>
// JavaScript program to implement
// the above approach
// Structure of
// a Trie node
class TrieNode
{
constructor()
{
this.idx = -1;
this.child = new Array(26);
for (let i = 0; i < 26; i++) {
// Update child[i]
this.child[i] = null;
}
}
}
// Function to insert a String into Trie
function Insert(root,str,i)
{
// Stores length of the String
let N = str.length;
// Traverse the String str
for (let j = 0; j < N; j++) {
// If str[i] not present in
// a Trie at current index
if (root.child[str[j].charCodeAt(0) -
'a'.charCodeAt(0)]==null) {
// Create a new node of Trie.
root.child[str[j].charCodeAt(0) -
'a'.charCodeAt(0)]
= new TrieNode();
}
// Update root
root = root.child[str[j].charCodeAt(0) -
'a'.charCodeAt(0)];
}
// Store index of str
// in the TrieNode
root.idx = i;
}
// Function to check if String str present
// in the Trie or not
function SearchString(root,str)
{
// Stores length of
// the String
let N = str.length;
// Traverse the String
for (let i = 0; i < N; i++) {
// If a character not present
// in Trie at current index
if (root.child[str[i].charCodeAt(0) -
'a'.charCodeAt(0)] == null) {
// Return str as
// unique String
return -1;
}
// Update root
root
= root.child[str[i].charCodeAt(0) -
'a'.charCodeAt(0)];
}
// Return index of str
return root.idx;
}
// Utility function to find the unique
// String in array of Strings
function UtilUniqStr(arr,N)
{
// Stores root node of the Trie
let root = new TrieNode();
// isUniq[i]: Check if i-th String
// is unique or not
let isUniq = new Array(N);
// Insert arr[0] into the Trie
Insert(root, arr[0], 0);
// Mark arr[0] as unique String
isUniq[0] = true;
// Traverse the given array
for (let i = 1; i < N; i++) {
// Stores previous 1st index
// of arr[i] in the array
let idx = SearchString(root,
arr[i]);
// If arr[i] not present
// in the Trie
if (idx == -1) {
// Mark i-th String
// as unique String
isUniq[i] = true;
// Insert arr[i] into Trie
Insert(root, arr[i], i);
}
// If arr[i] already present
// in the Trie
else {
// Mark i-th String as
// duplicate String in Trie
isUniq[idx] = false;
}
}
// Traverse the array
for (let i = 0; i < N; i++) {
// If i-th String is unique,
// then print the String
if (isUniq[i]) {
document.write(arr[i]+ " ");
}
}
}
// Driver Code
let arr=["geeks", "for",
"geek", "ab", "geek",
"for", "code", "karega" ];
let N = arr.length;
UtilUniqStr(arr, N);
// This code is contributed by patel2127
</script>
Producción:
geeks ab code karega
Complejidad de Tiempo: O(N * M), donde M es la longitud máxima de la string
Espacio Auxiliar: O(N * 26)
Publicación traducida automáticamente
Artículo escrito por sourav2901 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA