Sort the Given Array after Sorting Each Number Individually

Approach

To sort the integers individually, we need to sort the digits of the integer. But to sort digits of the integer, convert the integer to a string and then sort the string. It will result in a sorted number.

// function to sort a number int sortNumber(int n) { string s; //converting a number to corresponding string while(n!=0) { s += n%10+'0'; n/=10; } // if all digits are zero in the number if(s.size()==0) { s="0"; } sort(s.begin(),s.end()); //converting the sorted string to corresponding integer n=stoi(s); return n; } You can also try this code with Online C++ Compiler Run Code

After sorting each integer of the array, sort the array.

Code

//c++ code to sort the given Array after sorting each number individually #include<bits/stdc++.h> using namespace std; // sorting a number int sortNumber(int n) { string s; //converting a number to corresponding string while(n!=0) { s += n%10+'0'; n/=10; } // if all digits are zero in the number if(s.size()==0) { s="0"; } sort(s.begin(),s.end()); //converting the sorted string to corresponding integer n=stoi(s); return n; } //sorting the array after sorting each number vector<int> sortArr(vector<int> arr,int n) { //sorting the integers in the array individually for(int i=0;i<n;i++) { arr[i]=sortNumber(arr[i]); } //sorting the whole array sort(arr.begin(),arr.end()); return arr; } //driver code int main() { vector<int> arr{41,54,23,100,31}; arr=sortArr(arr,5); cout<<"The resulted array after the operations: "; for(int i=0;i<5;i++) { cout<<arr[i]<<" "; } } You can also try this code with Online C++ Compiler Run Code

Output

Complexity

The time complexity of the above implementation is O(nlogn) and space complexity is O(1).

Also see,  Rabin Karp Algorithm.

FAQs

1. What is stoi() in C++?
   stoi() takes a string as input and returns the corresponding integer value.
    
2. What is the difference between atoi() and stoi()?
   atoi() and stoi() both functions work similarly but atoi() takes an array of characters as input and stoi() can be used for an array of characters as well as string class in C++.
   atoi() is mostly used in the C programming language.
    
3. Which sorting algorithm is used to implement the STL sort() function?
   It uses a hybrid algorithm of quick sort, heap sort, and insertion sort. But by default, it is Quicksort that takes  O(nlogn) in the worst case.

Key Takeaways

This article covered how to sort the given array after sorting each number individually and implementing corresponding c++ code.

Recommended Readings:

• Binary Search
• Dynamic Programming
• Book Allocation Problem
• Plates Between Candles
• Find the subarray with t

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