CODEWITHSUNDEEP
javastringstringbuilder
Cerenium
Cerenium

Reputation: 31

Making a recursive method to print a text in java

I have to make a program which works like this. first it gets a number from input and then it gets (number) * strings.

for example:

2
a b

or

3
x1 x2 x3

then in the output it prints something like this:

Math.max(a, b)

or

Math.max(x1, Math.max(x2, x3))

I want to make Math.max method syntax with this code. I hope you understood!

Another Sample Input & output:

Input =

4
a b c d

Output =

Math.max(a, Math.max(b, Math.max(c, d)))

can someone help me?

The code I've wrote for it, can you suggest me some changes to make it better?

import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    int n = input.nextInt();
    String[] r = new String[n];
    for (int i = 0; i < n; i++) {
      r[i] = input.next();
    }
    printmax(r);

  }
  public static int i = 0 , j = 0;
  public static boolean last = false;
  public static void printmax(String [] r){
    if (last == true) {
      System.out.print(r[r.length - 1]);
      while (j < r.length - 1){ System.out.print(")");
        j++;
      }
    }
    if (r.length == 2) System.out.print("Math.max(" +r[0] + ", " + r[1] + ")");
    if (r.length > 2) {
      while (i < r.length -1) {
        if (i == r.length -2) last = true;
        System.out.print("Math.max(" + r[i] + ", ");
        i++;
        printmax(r);
      }
    }
  }
}

Upvotes: 1

Views: 540

Answers (2)

MOnkey
MOnkey

Reputation: 841

You can use the following code to achieve the above, here m calling maxElement() function recursively to achieve somthing like this Math.max(a, Math.max(b, Math.max(c, d)))

public static void main(String args[]){
    int length = 2; //here read the input from scanner
    String[] array = {"a", "b"}; //here read this input from scanner
    String max = maxElement(array,0,length);
    System.out.println(max);
}
    
public static String maxElement(String[] start, int index, int length) {
    if (index<length-1) {
        return "Math.max(" + start[index]  +  ", " + maxElement(start, index+1, length)+ ")";
    } else {
        return start[length-1];
    }
}

Output: Math.max(a, b)

Upvotes: 3

Omar Aldakar
Omar Aldakar

Reputation: 545

You need to do something like this.

First you define a function maxElement which takes your variable array as a parameter. 

public static maxElement(String[] variables) {
    return maxElementBis(variables,0);
}

Then you call a second function : maxElementBis which takes an additional argument which represents the index of the variable we are processing. 

public static String maxElementBis(String[] variables, int index) {
    if (variables.length < 2) 
        return "not enought variables";
    if (variables.length - index == 2)
        return "Math.max("+ variables[index]+","+variables[index + 1]+")";
    return "Math.max("+ variables[index]+","+maxElementBis(variables,index + 1)+")";

}

If the array contains less than two variables you cannot do what you want.

If you only have two variables left, this is your stop condition and you can directly return Math.max(v1,v2).

Otherwise you recursively call your function maxElementBis.

Upvotes: 1

Related Questions