Input Output from External File in C, C++, Java, and Python for Competitive Programming

In this article, we will learn about Input/Output from an external files in C/C++, Java, and Python for Competitive Programming.

Python I/O from the file

In python, the sys module is used to take input from a file and write output to the file. Let’s look at the implementation in the form of code.

Example

import sys
# For getting input
sys.stdin = open('sample.txt', 'r')
# Printing the Output
sys.stdout = open('sample.txt', 'w')

Java I/O from the file

Here we take the help of buffered reader method to take input associated with file reader to read input from file and print writer to print the data back to the file.

Example

// Java program For handling Input/Output
import java.io.*;
class Input {
   public static void main(String[] args) throws IOException {
      BufferedReader br = new BufferedReader(new
      FileReader("sampleinp.txt"));
      PrintWriter pw=new PrintWriter(new
      BufferedWriter(new
      FileWriter("sampleout.txt")));
      pw.flush();
   }
}

C/C++ I/O from a file

Here we take the help of free open() function and define the mode in which we want to open the file and what kind of operation we want to perform. By default mode is set to read-only

Example

#include<stdio.h>
int main() {
   // For getting input
   freopen("sampleinp.txt", stdin);
   // Printing the Output
   freopen("sampleout.txt", "w", stdout);
   return 0;
}

Conclusion

In this tutorial, we will learn about Input/Output from an external files in C/C++, Java, and Python for Competitive Programming.