📜  生成具有最长回文子串长度为K的N长度字符串

📅  最后修改于: 2021-04-26 07:09:54             🧑  作者: Mango

给定两个intgers(K≤N),该任务是获得长度N此字符串的一个回文子的,使得最大长度的字符串为K。

例子:

方法:该想法基于以下观察结果:由单个字符组成的任意长度的字符串始终是回文的,例如{‘a’,’bbbbb’,’ccc’}。因此,为了生成具有所需条件的字符串,请打印“ a” K次,以使其具有最长长度为K的回文子字符串,并以非回文序列填充其余的N – K个插槽。

请按照以下步骤解决问题:

  • 精确地打印“ a” K次。
  • 考虑一个非回文序列,例如“ bcd”。
  • 打印字符串。

下面是上述方法的实现:

C++
// C++ program to implement the above approach
 
#include 
using namespace std;
 
// Function to generate a string of
// length N having longest palindromic
// substring of length K
void string_palindrome(int N, int K)
{
 
    // Fill first K characters with 'a'
    for (int i = 0; i < K; i++)
        cout << "a";
 
    // Stores a non-palindromic sequence
    // to be repeated for N - k slots
    string s = "bcd";
 
    // Print N - k remaining characters
    for (int i = 0; i < N - K; i++)
        cout << s[i % 3];
}
 
// Driver Code
int main()
{
 
    // Given N and K
    int N = 5, K = 3;
    string_palindrome(N, K);
 
    return 0;
}


Java
// Java program to implement the above approach
import java.util.*;
 
class GFG
{
 
// Function to generate a String of
// length N having longest palindromic
// subString of length K
static void String_palindrome(int N, int K)
{
 
    // Fill first K characters with 'a'
    for (int i = 0; i < K; i++)
        System.out.print("a");
 
    // Stores a non-palindromic sequence
    // to be repeated for N - k slots
    String s = "bcd";
 
    // Print N - k remaining characters
    for (int i = 0; i < N - K; i++)
        System.out.print(s.charAt(i % 3));
}
 
// Driver Code
public static void main(String[] args)
{
 
    // Given N and K
    int N = 5, K = 3;
    String_palindrome(N, K);
}
}
 
// This code is contributed by 29AjayKumar


Python3
# Python3 program to implement the above approach
 
# Function to generate a string of
# length N having longest palindromic
# substring of length K
def string_palindrome(N, K):
 
    # Fill first K characters with 'a'
    for i in range(K):
        print("a", end = "")
 
    # Stores a non-palindromic sequence
    # to be repeated for N - k slots
    s = "bcd"
 
    # PrN - k remaining characters
    for i in range(N - K):
        print(s[i % 3], end = "")
 
# Driver Code
if __name__ == '__main__':
   
    # Given N and K
    N, K = 5, 3
    string_palindrome(N, K)
 
    # This code is contributed by mohit kumar 29


C#
// C# program to implement the above approach
using System;
class GFG
{
     
    // Function to generate a String of
    // length N having longest palindromic
    // subString of length K
    static void String_palindrome(int N, int K)
    {
     
        // Fill first K characters with 'a'
        for (int i = 0; i < K; i++)
            Console.Write("a");
     
        // Stores a non-palindromic sequence
        // to be repeated for N - k slots
        string s = "bcd";
     
        // Print N - k remaining characters
        for (int i = 0; i < N - K; i++)
            Console.Write(s[i % 3]);
    }
     
    // Driver Code
    public static void Main(string[] args)
    {
     
        // Given N and K
        int N = 5, K = 3;
        String_palindrome(N, K);
    }
}
 
// This code is contributed by AnkThon


Javascript


输出:
aaabc

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