Maximize Given Number by Replacing Digits in C++

Given the task is to maximize a given number with ‘N’ number of digits by replacing its digit using another array that contains 10 digits as an alternative for all single-digit numbers 0 to 9,

The given condition is that only a consecutive segment of numbers can be replaced and only once.

Input 

N=1234, arr[]={3 ,0 ,1 ,5 ,7 ,7 ,8 ,2 ,9 ,4}

Output 

1257

Explanation 

The number 3 can be replaced with its alternative 5= arr[3]

The number 4 can be replaced with its alternative 7= arr[4]

Input 

N=5183, arr[]={3 ,0 ,1 ,5 ,7 ,7 ,8 ,2 ,9 ,4}

Output 

7183

Approach used in the below program as follows

• In function Max() create a variable ‘N’ of type int to store the size of the number.

• Loop from i=0 till i<N and check for the number whose alternative is greater than it.

• Then replace the number with its alternative.

• Do this for the upcoming number until a number having a smaller alternative is not found

Example

#include <bits/stdc++.h>
using namespace std;
string Max(string str, int arr[]){
   int N = str.size();
   //Iterating till the end of string
   for (int i = 0; i < N; i++) {
      //Checking if it is greater or not
      if (str[i] - '0' < arr[str[i] - '0']) {
         int j = i;
         //Replacing with the alternate till smaller
         while (j < N && (str[j] - '0' <= arr[str[j] - '0'])) {
            str[j] = '0' + arr[str[j] - '0'];
            j++;
         }
         return str;
      }
   }
   // Returning original str if there is no change
   return str;
}
//Main function
int main(){
   string str = "2075";
   int arr[] = {3 ,0 ,1 ,5 ,7 ,7 ,8 ,2 ,9 ,4 };
   cout <<” Maximize the given number by replacing a segment of digits with the alternate digits given is: ” <<Max(str, arr);
   return 0;
}

Output

If we run the above code we will get the following output −

Maximize the given number by replacing a segment of digits with the alternate digits given is: 2375