Java program that takes as input three integers, a, b, and c, from the Java console and determines if they can be used in a correct arithmetic formula.

Problem:

Write a short program that takes as input three integers, a, b, and c, from the Java
console and determines if they can be used in a correct arithmetic formula (in the
given order), like “a+b = c,” “a = b−c,” or “a ∗ b = c.”

Solution:

package com.basics;

import java.io.ObjectInputStream.GetField;
import java.util.Scanner;

public class FormulaFormation {

static int a;
static int b;
static int c;

public static void main(String[] args) {
FormulaFormation arithmeticFormula = new FormulaFormation();
arithmeticFormula.getTheNumber();
float value = 1;
int oper2Range;
for (int i = 0; i < 4; i++) {
if (i < 2)
oper2Range = 4;
else
oper2Range = 2;
for (int j = 0; j < oper2Range; j++)
if ((value = valueOf(a, b, c, i, j)) == 0) {
System.out.print("Your inputs can form the equation: ");
displayEquation(i, j);
break;
}
}
if (value != 0)
System.out.println("Your inputs can't form any equation.");
}

private static float valueOf(int a, int b, int c, int oper1, int oper2) {
if (oper2 == 2 || oper2 == 3)
return calculate(a, calculate(b, c, oper2), oper1);
else
return calculate(c, calculate(a, b, oper1), oper2);
}

private static float calculate(float x, float y, int oper) {
switch (oper) {
case 0:
return x + y;
case 1:
return x - y;
case 2:
return x * y;
default:
return (float) x / y;
}
}

private static void displayEquation(int oper1, int oper2) {
if (oper1 == 0 || oper1 == 1)
// a +- b */ c = 0 -> a = -+ b * c
if (oper2 == 2 || oper2 == 3)
System.out.printf("a = %cb %c c\n",
(toChar(oper1) == '+') ? '-' : '\u0000', toChar(oper2));
// a +- b +- c = 0 -> a +- b = -+ c
else
System.out.printf("a %c b = %cc\n", toChar(oper1),
(toChar(oper2) == '+') ? '-' : '\u0000');
// a */ b +- c = 0 -> a */b = -+ c
else
System.out.printf("a %c b = %cc\n", toChar(oper1),
(toChar(oper2) == '+') ? '-' : '\u0000');
}


private static char toChar(int operator) {
switch (operator) {
case 0:
return '+';
case 1:
return '-';
case 2:
return '*';
default:
return '/';
}
}

public void getTheNumber() {
Scanner scanner = new Scanner(System.in);
System.out.println("enter number a: ");
a = scanner.nextInt();
System.out.println("enter number b: ");
b = scanner.nextInt();
System.out.println("enter number c: ");
c = scanner.nextInt();
scanner.close();
}

}

Output:

enter number a:
1
enter number b:
1
enter number c:
1
Your inputs can form the equation: a = b * c
Your inputs can form the equation: a * b = c
Your inputs can form the equation: a / b = c