How Can I Insert Zeros in the Middle of a String of IP? C/C++

I wrote a piece of code that does the following:

1. Get IP from user in this format xx.xx.xx.xx
2. Fill zeros at the left of each segment if user did not enter 3 digits on the set, e.g.
0xx.00x.xxx.0xx

Input is: 22.3.120.32
Output should be: 022.003.120.032

Here is my code, it works but not perfectly. When user inserts 111.33.66.3, nothing happens, it works when the first segment is not 3 numbers, there are many other flaws too.

Here is my code

Code:

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#include <iostream>
#include<string>
using namespace std;
 
const int MAX_IP_SIZE = 15;
const int MAX_IP_DIGIT = 3;
 
int main ()
{
        string IP;
        int numOfZerosToFill = 0;
        int tempDigitCount = 0;
        int IPCurrentPointer = 0;
 
        cout<<"ENTER IP: ";
        cin>>IP;
 
        while (IPCurrentPointer < (int)IP.length())
        {
                char dot = IP.at(IPCurrentPointer);
           
                if(dot == '.')
                {
                        numOfZerosToFill = MAX_IP_DIGIT - tempDigitCount;
                     
                        if( numOfZerosToFill == 1 || numOfZerosToFill == 2)
                        {
                                int spotForFillingZeros = IPCurrentPointer - tempDigitCount;
                                IP.insert(spotForFillingZeros, numOfZerosToFill, '0');
                                IPCurrentPointer += numOfZerosToFill;
                             
                                tempDigitCount = 0;
                        }
                }
                else
                        tempDigitCount++;
 
                IPCurrentPointer++;
        }
 
        numOfZerosToFill = MAX_IP_DIGIT - tempDigitCount;
        if( numOfZerosToFill == 1 || numOfZerosToFill == 2)
        {
                int spotForFillingZeros = IPCurrentPointer - tempDigitCount;
                IP.insert(spotForFillingZeros, numOfZerosToFill, '0');
                IPCurrentPointer += numOfZerosToFill;
        }
 
        cout<<IP<<"******"<<endl;
        system("pause");
        return 0;
}

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Do you have a better algorithm? Please note that i will receive the IP from a parameter ready & then pass it to a function that inserts zeros on the front if possible. The piece of code above is a sample out of a bigger source code.


Thanks

Use sprintf to format.

Code:

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sprintf (strResult, "%03s", strIpSegment);

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if IpSegment is '12', strResult will be '012'.