FruitBasket

// This code is for Java 7
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
import java.security.*;

public class Solution {
    
    public static Map<String, Integer> fruitBasket;
    static {
        fruitBasket = new HashMap<>();
        fruitBasket.put("apple", 3);
        fruitBasket.put("banana", 1);
        fruitBasket.put("orange", 2);
    }
    
    public static String fruitPicker(Map<String, Integer> fruitBasket) {
        Set<String> keys = fruitBasket.keySet();
        List<String> allFruiteNames = new ArrayList<>();
        for(String fruitName : keys){
            int fruitQuantity = fruitBasket.get(fruitName);
            for(int i = 0; i < fruitQuantity; i++){
                allFruiteNames.add(fruitName);
            }
        }
        
        int randomIndex = new SecureRandom().nextInt(allFruiteNames.size());
        String randomFruit = allFruiteNames.get(randomIndex);
        
        return randomFruit;
    }
    
    public static void testFruitPicker(Map<String, Integer> fruitBasket, int runTime){
        final float acceptedDiff = 0.5f;
        Map<String, Integer> selectedTable = new HashMap<>();
        
        
    }

    public static void main(String[] args) {
        
        // How many time to run: runTime
        // How many time the fruitHappend: selectedTime(3)
        // How many percentage for this lottery: thatFruitQuantity(3) / totalFruit(6) = expectedPercentage
        // Expectation: (selectedTime/runTime) ~= expectedPercentage (+/- some percentage)
        
        // banana for example
        // 10 runs, fruit happened 1; expected would be 1.6
        // selected / run = .1 >= .16666
        
        // +/- 5%
        // Used for testing.
        
        final float acceptedDiff = 0.5f;
        Map<String, Integer> selectedTable = new HashMap<>();
        
        // Put the frequency of selection
        int runTime = 1000;
        for (int i = 0; i < runTime; i++) {
            String randomFruit = fruitPicker(fruitBasket);
            if(selectedTable.containsKey(randomFruit)){
                selectedTable.put(randomFruit, selectedTable.get(randomFruit) + 1);
            } else {
                selectedTable.put(randomFruit, 1);
            }
        }
        
        // Calculate fruit quantity from the basket
        int totalFruit = 0;
        for(String fruit : fruitBasket.keySet()){
            totalFruit += fruitBasket.get(fruit);
        }
        
        // Verification
        for(String fruitName : selectedTable.keySet()){
            float expectedPercentage = fruitBasket.get(fruitName) / totalFruit ;
            int selectedTime = selectedTable.get(fruitName);
            float happenedPercentage = selectedTime / runTime ;
            
            boolean isAllowPercentage = Math.abs(expectedPercentage - happenedPercentage) <= acceptedDiff;
            System.out.println(fruitName + ": " + isAllowPercentage);
        }
        
    }
}