Premise
The needed imports should be already provided, in any case be sure to include:
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import java.io.*; // for BufferedWriter
import java.util.*; // for Scanner
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Reading values
For reading we can use the java.util.Scanner class. We can create it in the main method.
Remember to close it at the end.
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public static void main(String[] args){
Scanner scanner = new Scanner(System.in);
//data reading code
scanner.close();
}
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We can use this class to read full lines or single values
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String s = scanner.nextLine();
int i = scanner.nextInt();
double d = scanner.nextDouble();
byte b = scanner.nextByte();
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Reading an array of N elements
The first line contains N, the number of elements.
The next line contains N space-separated integers.
We can read data either in an array or a list.
Read to array:
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int lenght = scanner.nextInt();
int[] arr = new int[lenght];
for (int i= 0; i < lenght; i++){
arr[i] = scanner.nextInt();
}
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Read to List:
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scanner.nextLine(); //Skip the first line, we do not need length info.
List list = new ArrayList<Integer>();
while (scanner.hasNextInt()){
list.add(scanner.nextInt());
}
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Output
To print data to output we can use the java.io.bufferedWriter class
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BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
bufferedWriter.write(String.valueOf(result));
bufferedWriter.newLine();
bufferedWriter.close();
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Full snippet
Full snippet to read a single line and print a result.
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import java.io.BufferedWriter;
import java.io.FileWriter;
import java.util.Scanner;
public class Solution {
private static String doStuff(String param){
//Do your things here!
return param;
}
public static void main(String[] args) throws Exception {
Scanner scanner = new Scanner("my test string");
String param = scanner.nextLine();
String result = doStuff(param);
BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
bufferedWriter.write(String.valueOf(result));
bufferedWriter.newLine();
bufferedWriter.close();
scanner.close();
}
}
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