Dada una array de strings arr[] de tamaño N donde cada string consta solo de letras minúsculas en inglés. La tarea es devolver el recuento de todas las strings palindrómicas en la array.
Ejemplos:
Entrada: arr[] = {“abc”,”car”,”ada”,”racecar”,”cool”}
Salida: 2
Explicación: “ada” y “racecar” son las dos strings palíndromo.Entrada: arr[] = {“def”,”aba”}
Salida: 1
Explicación: “aba” es la única string palíndromo.
Enfoque: La solución se basa en el enfoque codicioso . Verifique cada string de una array si es palíndromo o no y también realice un seguimiento del conteo. Siga los pasos a continuación para resolver el problema:
- Inicialice una variable de conteo como 0.
- Itere sobre el rango [0, N) usando la variable i y si arr[i] es un palíndromo, entonces incremente el valor de ans.
- Después de realizar los pasos anteriores, imprima el valor de ans como respuesta.
A continuación se muestra la implementación del enfoque anterior.
C++
// C++ program for the above approach
#include <bits/stdc++.h>
using namespace std;
// Function to check if given string
// is Palindrome or not
bool isPalindrome(string& s)
{
// Copy string s char into string a
string a = s;
reverse(s.begin(), s.end());
// Check if two string are equal or not
return s == a;
}
// Function to return count
// of Palindrome string
int PalindromicStrings(string arr[], int N)
{
int ans = 0;
// Loop to find palindrome string
for (int i = 0; i < N; i++) {
// Checking if given string is
// palindrome or not
if (isPalindrome(arr[i])) {
// Update answer variable
ans++;
}
}
return ans;
}
// Driver Code
int main()
{
string arr[]
= { "abc", "car", "ada",
"racecar", "cool" };
int N = sizeof(arr) / sizeof(arr[0]);
// Print required answer
cout << PalindromicStrings(arr, N);
return 0;
}
Java
// java program for the above approach
class GFG
{
// Function to check if given String
// is Palindrome or not
static boolean isPalindrome(String str)
{
// Start from leftmost and rightmost corners of str
int l = 0;
int h = str.length() - 1;
// Keep comparing characters while they are same
while (h > l)
{
if (str.charAt(l++) != str.charAt(h--))
{
return false;
}
}
return true;
}
// Function to return all Palindrome String
static int PalindromicStrings(String []arr,
int N)
{
int ans = 0;
// Loop to find palindrome String
for (int i = 0; i < N; i++) {
// Checking if given String is
// palindrome or not
if (isPalindrome(arr[i])) {
// Update answer variable
ans++;
}
}
return ans;
}
// Driver Code
public static void main(String[] args)
{
String []arr
= { "abc", "car", "ada", "racecar", "cool" };
int N = arr.length;
System.out.print(PalindromicStrings(arr, N));
}
}
// This code is contributed by Rajput-Ji
Python3
# Python program for the above approach # Function to check if given String # is Palindrome or not def isPalindrome(str): # Start from leftmost and rightmost corners of str l = 0; h = len(str) - 1; # Keep comparing characters while they are same while (h > l): if (str[l] != str[h]): return False; l += 1; h -= 1; return True; # Function to return all Palindrome String def PalindromicStrings(arr, N): ans = 0; # Loop to find palindrome String for i in range(N): # Checking if given String is # palindrome or not if (isPalindrome(arr[i])): # Update answer variable ans += 1; return ans; # Driver Code if __name__ == '__main__': arr = ["abc", "car", "ada", "racecar", "cool"]; N = len(arr); print(PalindromicStrings(arr, N)); # This code is contributed by 29AjayKumar
C#
// C# program for the above approach
using System;
using System.Collections;
class GFG
{
// Function to check if given string
// is Palindrome or not
static bool isPalindrome(string str)
{
// Start from leftmost and rightmost corners of str
int l = 0;
int h = str.Length - 1;
// Keep comparing characters while they are same
while (h > l)
{
if (str[l++] != str[h--])
{
return false;
}
}
return true;
}
// Function to return all Palindrome string
static int PalindromicStrings(string []arr,
int N)
{
int ans = 0;
// Loop to find palindrome string
for (int i = 0; i < N; i++) {
// Checking if given string is
// palindrome or not
if (isPalindrome(arr[i])) {
// Update answer variable
ans++;
}
}
return ans;
}
// Driver Code
public static void Main()
{
string []arr
= { "abc", "car", "ada", "racecar", "cool" };
int N = arr.Length;
Console.Write(PalindromicStrings(arr, N));
}
}
// This code is contributed by Samim Hossain Mondal.
Javascript
<script>
// Javascript program for the above approach
// Function to check if given string
// is Palindrome or not
function isPalindrome(s)
{
// Copy string s char into string a
let a = s;
s = s.split("").reverse().join("");
// Check if two string are equal or not
return s == a;
}
// Function to return count
// of Palindrome string
function PalindromicStrings(arr, N) {
let ans = 0;
// Loop to find palindrome string
for (let i = 0; i < N; i++) {
// Checking if given string is
// palindrome or not
if (isPalindrome(arr[i])) {
// Update answer variable
ans++;
}
}
return ans;
}
// Driver Code
let arr = ["abc", "car", "ada", "racecar", "cool"];
let N = arr.length;
// Print required answer
document.write(PalindromicStrings(arr, N));
// This code is contributed by saurabh_jaiswal.
</script>
Producción
2
Complejidad de Tiempo: O(N * W) donde W es la longitud promedio de las strings
Espacio Auxiliar: O(1), ya que no se ha tomado espacio extra.