在中间插入成对绝对差后，通过从两端选择最大值来创建新的手机号码

给定一个字符串ph[] ，任务是找到连续元素的绝对差并将结果插入连续元素之间。通过这样做，电话号码的大小将从10增加到19 。现在我们必须比较第一个和最后一个数字并选择最大值，这样我们将获得一个新的电话号码。

例子：

Input: ph = “9647253846”
Output: 9364857553
Explanation:

Input: ph = “7635892563”
Output: 7363535791

方法：这个想法是使用两个指针的方法来解决这个问题，同时使用一个字符串变量来添加不同的电话号码。请按照以下步骤解决问题：

• 将字符串变量S[]初始化为空字符串。
• 使用变量i遍历范围[0, N-1)并执行以下任务：
  • 将ph[i]添加到变量S。
  • 将变量s初始化为int(ph[i]) – int(ph[i+1])并将x初始化为abs(s)。
  • 将str(x)添加到变量S。
• 将ph[9]添加到变量S。
• 将变量s初始化为0 ，将e初始化为len(S)-1。
• 将字符串变量ph2[]初始化为空字符串。
• 在while循环中遍历直到s不等于e并执行以下任务：
  • 将S[s]或S[e]的最大值添加到变量ph2[]。
  • 将s的值加1 ，将e的值减1。
• 将S[e]添加到变量ph2[]。
• 执行上述步骤后，打印ph2[]的值作为答案。

下面是上述方法的实现。

C++

// C++ program for the above approach
#include 
using namespace std;
 
// Function to create the phone number
string phNumber(string ph, int n)
{
 
    // Empty string to store extended number
    string S = "";
 
    // Loop for extend phone number
    for (int i = 0; i < n - 1; i++) {
 
        // Add character form string
        S += ph[i];
 
        // Finding absolute difference
        int x = abs(ph[i] - ph[i + 1]);
 
        // Adding the difference to S
        S += to_string(x);
    }
    // Adding last digit of ph
    S += ph[9];
 
    // Using 2 pointer algorithm to form comparison
 
    // s is start index
    int s = 0;
 
    // e is end index
    int e = S.length() - 1;
 
    // ph2 an empty string for
    // storing the the phone number
    string ph2 = "";
 
    // Loop till e become equal to s
    while (s != e) {
 
        // Comparing element at s and e
        // index and adding maximum
 
        if (S[s] > S[e]) {
            ph2 += S[s];
        }
        else {
            ph2 += S[e];
        }
        // Increment start index
        s += 1;
 
        // Decrement end index
        e -= 1;
    }
    // When s = e loop will terminate
    // so adding element at index s = e
    ph2 += S[e];
    // Return phone number
    return ph2;
}
 
// Driver Code
int main()
{
   
    // Original phone number
    string ph = "9647253846";
 
    // Calling function to create new number
    string num = phNumber(ph, ph.length());
 
    // Print the new number
    cout << num;
}
 
// This code is contributed by Samim Hossain Mondal.

Java

// Java program for the above approach
class GFG {
 
  // Function to create the phone number
  static String phNumber(String ph, int n) {
 
    // Empty string to store extended number
    String S = "";
 
    // Loop for extend phone number
    for (int i = 0; i < n - 1; i++) {
 
      // Add character form string
      S += ph.charAt(i);
 
      // Finding absolute difference
      int x = Math.abs(ph.charAt(i) - ph.charAt(i + 1));
 
      // Adding the difference to S
      S += Integer.toString(x);
    }
    // Adding last digit of ph
    S += ph.charAt(9);
 
    // Using 2 pointer algorithm to form comparison
 
    // s is start index
    int s = 0;
 
    // e is end index
    int e = S.length() - 1;
 
    // ph2 an empty string for
    // storing the the phone number
    String ph2 = "";
 
    // Loop till e become equal to s
    while (s != e) {
 
      // Comparing element at s and e
      // index and adding maximum
 
      if (S.charAt(s) > S.charAt(e)) {
        ph2 += S.charAt(s);
      } else {
        ph2 += S.charAt(e);
      }
      // Increment start index
      s += 1;
 
      // Decrement end index
      e -= 1;
    }
    // When s = e loop will terminate
    // so adding element at index s = e
    ph2 += S.charAt(e);
    // Return phone number
    return ph2;
  }
 
  // Driver Code
  public static void main(String args[]) {
 
    // Original phone number
    String ph = "9647253846";
 
    // Calling function to create new number
    String num = phNumber(ph, ph.length());
 
    // Print the new number
    System.out.println(num);
  }
}
 
// This code is contributed by gfgking

Python3

# Function to create the phone number
def phNumber(ph, n):
   
    # Empty string to store extended number
    S =""
     
    # Loop for extend phone number
    for i in range(n-1):
       
          # Add character form string
        S+= ph[i]
         
        # Finding absolute difference
        s = int(ph[i])-int(ph[i + 1])
        x = abs(s)
         
        # Adding the difference to S
        S+= str(x)
     
    # Adding last digit of ph
    S+= ph[9]
 
    # Using 2 pointer algorithm to form comparison
     
    # s is start index
    s = 0
     
    # e is end index
    e = len(S)-1
     
    # ph2 an empty string for
    # storing the the phone number
    ph2 =""
     
    # Loop till e become equal to s
    while s != e:
         
        # Comparing element at s and e
        # index and adding maximum
        ph2+= max(S[s], S[e])
         
        # Increment start index
        s+= 1
         
        # Decrement end index
        e-= 1
         
    # When s = e loop will terminate
    # so adding element at index s = e
    ph2+= S[e]
 
    # Return phone number
    return ph2
   
# Original phone number
ph = "9647253846"
 
# Calling function to create new number
num = phNumber(ph, len(ph))
 
# Print the new number
print(num)

C#

// C# program for the above approach
using System;
 
class GFG {
 
  // Function to create the phone number
  static string phNumber(string ph, int n)
  {
 
    // Empty string to store extended number
    string S = "";
 
    // Loop for extend phone number
    for (int i = 0; i < n - 1; i++) {
 
      // Add character form string
      S += ph[i];
 
      // Finding absolute difference
      int x = Math.Abs(ph[i] - ph[i + 1]);
 
      // Adding the difference to S
      S += x.ToString();
    }
    // Adding last digit of ph
    S += ph[9];
 
    // Using 2 pointer algorithm to form comparison
 
    // s is start index
    int s = 0;
 
    // e is end index
    int e = S.Length - 1;
 
    // ph2 an empty string for
    // storing the the phone number
    string ph2 = "";
 
    // Loop till e become equal to s
    while (s != e) {
 
      // Comparing element at s and e
      // index and adding maximum
 
      if (S[s] > S[e]) {
        ph2 += S[s];
      }
      else {
        ph2 += S[e];
      }
      // Increment start index
      s += 1;
 
      // Decrement end index
      e -= 1;
    }
    // When s = e loop will terminate
    // so adding element at index s = e
    ph2 += S[e];
    // Return phone number
    return ph2;
  }
 
  // Driver Code
  public static void Main()
  {
 
    // Original phone number
    string ph = "9647253846";
 
    // Calling function to create new number
    string num = phNumber(ph, ph.Length);
 
    // Print the new number
    Console.Write(num);
  }
}
 
// This code is contributed by ukasp.

Javascript

       // JavaScript code for the above approach
 
       // Function to create the phone number
       function phNumber(ph, n) {
 
           // Empty string to store extended number
           let S = ""
 
           // Loop for extend phone number
           for (let i = 0; i < n - 1; i++) {
 
               // Add character form string
               S += ph[i]
 
               // Finding absolute difference
               let s = ph[i].charCodeAt(0) - ph[i + 1].charCodeAt(0)
               let x = Math.abs(s)
 
               // Adding the difference to S
               S += x.toString();
           }
           // Adding last digit of ph
           S += ph[9]
 
           // Using 2 pointer algorithm to form comparison
 
           // s is start index
           s = 0
 
           // e is end index
           e = S.length - 1
 
           // ph2 an empty string for
           // storing the the phone number
           ph2 = ""
 
           // Loop till e become equal to s
           while (s != e) {
 
               // Comparing element at s and e
               // index and adding maximum
 
               if (S[s].charCodeAt(0) > S[e].charCodeAt(0)) {
                   ph2 += S[s];
               }
               else {
                   ph2 += S[e];
               }
               // Increment start index
               s += 1
 
               // Decrement end index
               e -= 1
 
 
           }
           // When s = e loop will terminate
           // so adding element at index s = e
           ph2 += S[e]
           // Return phone number
           return ph2
       }
       // Original phone number
       let ph = "9647253846"
 
       // Calling function to create new number
       let num = phNumber(ph, ph.length)
 
       // Print the new number
       document.write(num)
 
 // This code is contributed by Potta Lokesh
   

输出

9364857553

时间复杂度： O(N)
辅助空间： O(N)