通过只改变一个字符将字符串转换为回文字符串

给定一个字符串str。检查是否可以通过仅更改一个字符将字符串转换为回文字符串。
例子：

Input : str = "abccaa"
Output : Yes
We can change the second last character
i.e. 'a' to 'b' to make it palindrome string

Input : str = "abbcca"
Output : No
We can not convert the string into palindrome
string by changing only one character.

方法：想法很简单，我们用str[ni-1]检查字符str[i]。如果有不匹配，我们增加计数。如果不匹配的计数超过 1，我们返回 false。否则我们返回真。
以下是上述想法的实现：

C++

// CPP program to Check if it is
// possible to convert the string
// into palindrome string by changing
// only one character.
#include
using namespace std;
 
// Function to check if it is possible
// to convert the string into palindrome
bool checkPalindrome(string str){
     
    int n = str.length();       
   
    // Counting number of characters
    // that should be changed.
    int count = 0;
    for (int i = 0; i < n/2; ++i)
        if (str[i] != str[n - i - 1])
            ++count;
     
    // If count of changes is less than
    // or equal to 1
    return (count <= 1);
}
 
// Driver function.
int main()
{
    string str = "abccaa";   
    if (checkPalindrome(str))
       cout << "Yes" << endl;
    else
       cout << "No" << endl;
     
    return 0;
}

Java

// Java program to Check if it is
// possible to convert the string
// into palindrome string by changing
// only one character.
import java.io.*;
 
class GFG {
     
    // Function to check if it is possible
    // to convert the string into palindrome
    static boolean checkPalindrome(String str){
     
    int n = str.length();    
 
    // Counting number of characters
    // that should be changed.
    int count = 0;
     
    for (int i = 0; i < n/2; ++i)
     
        if (str.charAt(i) != str.charAt(n - i - 1))
            ++count;
     
    // If count of changes is less than
    // or equal to 1
    return (count <= 1);
    }
     
// Driver Function   
public static void main(String[] args) {
     
    String str = "abccaa";
         
    if (checkPalindrome(str))
     
        System.out.println("Yes");
    else
        System.out.println("No");
         
    }
     
}
 
// This code is contributed by vt_m

Python3

# Python program to Check
# if it is possible to
# convert the string into
# palindrome string by
# changing only one character.
 
# Function to check if
# it is possible to
# convert the string
# into palindrome
def checkPalindrome(str) :
     
    n = len(str)
     
    # Counting number of
    # characters that
    # should be changed.
    count = 0
    for i in range(0, int(n / 2)) :
        if (str[i] != str[n - i - 1]) :
            count = count + 1
     
    # If count of changes
    # is less than
    # or equal to 1
    if(count <= 1) :
        return True
    else :
        return False
 
# Driver Code
str = "abccaa"
if (checkPalindrome(str)) :
    print ("Yes")
else :
    print ("No")
     
# This code is contributed by
# Manish Shaw(manishshaw1)

C#

// C# program to Check if it is
// possible to convert the string
// into palindrome string by changing
// only one character.
using System;
 
class GFG {
     
    // Function to check if it is possible
    // to convert the string into palindrome
    static bool checkPalindrome(string str){
     
        int n = str.Length;
 
        // Counting number of characters
        // that should be changed.
        int count = 0;
         
        for (int i = 0; i < n / 2; ++i)
         
            if (str[i] != str[n - i - 1])
                ++count;
         
        // If count of changes is less than
        // or equal to 1
        return (count <= 1);
    }
     
    // Driver Function
    public static void Main()
    {     
        string str = "abccaa";
             
        if (checkPalindrome(str))
         
            Console.WriteLine("Yes");
        else
            Console.WriteLine("No");
             
        }
     
}
 
// This code is contributed by vt_m

PHP

Javascript

输出：

Yes