Google Interview Question for SDETs


Country: United States
Interview Type: Phone Interview




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1
of 1 vote

import java.util.*;
import org.junit.*;
import junit.framework.TestCase;
import static org.junit.Assert.assertEquals;

/**
 *  |1,2,3|
 *  |4,5,6|
 *  |7,8,9|
 *  |0|
 */

public class CalculatorExample extends TestCase{
	int[][] calculator= {{1,2,3},{4,5,6},{7,8,9},{0}};
	int[][] LMove= {{-1,-2},
			{-1,2},
			{1,2},
			{1,-2},
			{-2,-1},
			{-2,1},
			{2,-1},
			{2,1}};
	

	public int[] getXYByNumber(int number) {
		int[] returnArray = new int[2];
		if (number==0) {
			returnArray[0]=3;
			returnArray[1]=0;
			return returnArray;
		}
		for (int i=0; i <3; i++) {
			for (int j=0; j<3; j++) {
				if (calculator[i][j]==number) {

					returnArray[0]=i;
					returnArray[1]=j;
					break;
				}
			}
		}
		return returnArray;
	}
	
	public int getNumberByXY(int x, int y) {
		try {
			if ((x==3)&&(y<0)&&(y>3))
				return 0;
			if ((x<0)&&(x>4))
				return -1;
			if ((y<0)&&(y>3))
				return -1;
			return calculator[x][y];
		}catch(Exception e) {
			return -1;
		}

	}
	
	public Set getAllLMoveNumber(int start) {
		Set<Integer> set = new HashSet();
		int[] xy=getXYByNumber(start);
		for (int[] move : LMove) {
			int x=xy[0]+move[0];
			int y=xy[1]+move[1];
			if (getNumberByXY(x,y)!=-1){
				//System.out.println("x:"+x+",y:"+y);
				//System.out.println("x:"+x+",y:"+y+",number:"+getNumberByXY(x,y));
				set.add(getNumberByXY(x,y));
			}
		}
		return set;
	}
	

	public void inputNumber(int input) {
		//System.out.println("input:"+input);
		Iterator itr = getAllLMoveNumber(input).iterator();
		while(itr.hasNext())
			System.out.println("Input ["+input+"]"+itr.next());
	}
	
	public void test_allPossibleNumber() {
		inputNumber(1);
		inputNumber(2);
		inputNumber(3);
		inputNumber(4);
		inputNumber(5);
		inputNumber(6);
		inputNumber(7);
		inputNumber(8);
		inputNumber(9);
		inputNumber(0);
	}
		
}

Output:
Input [1]6
Input [1]8
Input [2]7
Input [2]9
Input [3]4
Input [3]8
Input [4]3
Input [4]9
Input [5]0
Input [6]1
Input [6]7
Input [7]2
Input [7]6
Input [8]1
Input [8]3
Input [9]0
Input [9]2
Input [9]4
Input [0]5
Input [0]9

- wingchuihk November 08, 2017 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

5 doesn't have any @wingchuihk.

- Aditya April 19, 2018 | Flag Reply
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0
of 0 vote

import java.util.*;
public class HelloWorld{

     public static void main(String []args){
   
      generate(6); 
     }
     
     
     public static void generate(int number){
         
        HashMap<Integer, HashMap<String, Integer>> cache = new HashMap<Integer, HashMap<String, Integer>>();
        
        cache.put(0, new HashMap<String, Integer>());
        cache.get(0).put("x", 3);
        cache.get(0).put("y", 2);
        
        cache.put(1, new HashMap<String, Integer>());
        cache.get(1).put("x", 2);
        cache.get(1).put("y", 1);
        
        cache.put(2, new HashMap<String, Integer>());
        cache.get(2).put("x", 2);
        cache.get(2).put("y", 2);
        
        cache.put(3, new HashMap<String, Integer>());
        cache.get(3).put("x", 2);
        cache.get(3).put("y", 3);
        
        cache.put(4, new HashMap<String, Integer>());
        cache.get(4).put("x", 1);
        cache.get(4).put("y", 1);
        
        cache.put(5, new HashMap<String, Integer>());
        cache.get(5).put("x", 1);
        cache.get(5).put("y", 2);
        
        cache.put(6, new HashMap<String, Integer>());
        cache.get(6).put("x", 1);
        cache.get(6).put("y", 3);
        
        cache.put(7, new HashMap<String, Integer>());
        cache.get(7).put("x", 0);
        cache.get(7).put("y", 1);
        
        cache.put(8, new HashMap<String, Integer>());
        cache.get(8).put("x", 0);
        cache.get(8).put("y", 2);
        
        cache.put(9, new HashMap<String, Integer>());
        cache.get(9).put("x", 0);
        cache.get(9).put("y", 3);
            
            int[][] LMove= {{-1,-2},
			{-1,2},
			{1,2},
			{1,-2},
			{-2,-1},
			{-2,1},
			{2,-1},
			{2,1}};
			
		int currentX = cache.get(number).get("x");
		int currentY = cache.get(number).get("y");
		
		for (int[] move : LMove) {
		    
		    int destX = currentX + move[0];
		    int destY = currentY + move[1];
		    
		    HashMap<String, Integer> point= new HashMap<String, Integer>();
		    
		    point.put("x", destX);
		    point.put("y", destY);
		    int destNum = getKeyFromValue(cache, point);
		    if(destNum !=10){
		        
		        System.out.println(destNum);
		        
		    }
		    
		}
      
         
     }
     
     public static int getKeyFromValue(HashMap hm, Object value) {
        for (Object o : hm.keySet()) {
            if (hm.get(o).equals(value)) {
                
                int i = (int) o;
                return i;
            }
        }
    return 10;
  }
}

- Aditya April 19, 2018 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

@Aditya
The phone number actually have 0 under the 8 like below. And 5 does not fulfilled the rule. Therefore it has none.
|1,2,3|
|4,5,6|
|7,8,9|
| ,0, |

- wingchuihk June 02, 2018 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

Its a simple co-ordinate geometry problem. You can use mod 3 and solve it easily

/**
 *  |1,2,3|
 *  |4,5,6|
 *  |7,8,9|
 *  |0|
 */
public class KnightMoveInCalc{

    private static void find(int num) {
        if(num<0) return;
        int x = num%3-1;
        int y = num/3;
        if(num == 0) {
            x = 4;
            y = 0;
        }


        int[] dxs = {1,2,-1,-2};
        int[] dys = {1,2,-1,-2};
        for(int dx:dxs) {
            for(int dy:dys) {
                if(Math.abs(dx)!=Math.abs(dy)) {
                    if((x+dx)>=0 && (x+dx)<3 &&
                            (y+dy)>=0 && (y+dy)<3) {
                        System.out.println((y+dy)*3+(x+dx)+1);
                    } else if((y+dy)==3 && (x+dx)==0) {
                        System.out.println("0");
                    }
                }
            }
        }
    }

    public static void main(String[] args) {
        find(5);
    }
}

- Ganesh July 15, 2018 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

Its a simple geometry problem, use mod3 and solve it.

/**
 *  |1,2,3|
 *  |4,5,6|
 *  |7,8,9|
 *  |0|
 */
public class KnightMoveInCalc{

    private static void find(int num) {
        if(num<0) return;
        int x = num%3-1;
        int y = num/3;
        if(num == 0) {
            x = 4;
            y = 0;
        }


        int[] dxs = {1,2,-1,-2};
        int[] dys = {1,2,-1,-2};
        for(int dx:dxs) {
            for(int dy:dys) {
                if(Math.abs(dx)!=Math.abs(dy)) {
                    if((x+dx)>=0 && (x+dx)<3 &&
                            (y+dy)>=0 && (y+dy)<3) {
                        System.out.println((y+dy)*3+(x+dx)+1);
                    } else if((y+dy)==3 && (x+dx)==0) {
                        System.out.println("0");
                    }
                }
            }
        }
    }

    public static void main(String[] args) {
        find(5);
    }
}

- Ganesh Bhat July 15, 2018 | Flag Reply
Comment hidden because of low score. Click to expand.
0
of 0 vote

package sk.radobenc.exercises;

import java.util.HashMap;
import java.util.Map;

/*
 1 2 3
 4 5 6
 7 8 9
 0
 To adjust 0 position, fix the respective element in map m below.
 */
public class NumberPad {

	static class Pos {
		private final int row;
		private final int column;

		Pos(int row, int column) {
			this.row = row;
			this.column = column;
		}

		@Override
		public boolean equals(Object obj) {
			Pos p = (Pos) obj;
			return column == p.column && row == p.row;
		}

		@Override
		public int hashCode() {
			return 31 * (31 + column) + row;
		}

		@Override
		public String toString() {
			return new StringBuilder().append('[').append(row).append(',').append(column).append(']').toString();
		}
	}

	public static void main(String[] args) {
		Map<Pos, Integer> m = new HashMap<Pos, Integer>();
		m.put(new Pos(0, 0), 1);
		m.put(new Pos(0, 1), 2);
		m.put(new Pos(0, 2), 3);
		m.put(new Pos(1, 0), 4);
		m.put(new Pos(1, 1), 5);
		m.put(new Pos(1, 2), 6);
		m.put(new Pos(2, 0), 7);
		m.put(new Pos(2, 1), 8);
		m.put(new Pos(2, 2), 9);
		m.put(new Pos(3, 0), 0);
		Map<Integer, Pos> revM = new HashMap<Integer, Pos>();
		for (Map.Entry<Pos, Integer> e : m.entrySet()) {
			revM.put(e.getValue(), e.getKey());
		}
		int[][] moves = { { 2, 1 }, { 2, -1 }, { 1, -2 }, { 1, 2 }, { -1, -2 }, { -1, 2 }, { -2, -1 }, { -2, 1 } };
		for (int i = 0; i < 10; i++) {
			for (int j = 0; j < moves.length; j++) {
				Pos source = revM.get(i);
				Pos target = new Pos(source.row + moves[j][0], source.column + moves[j][1]);
				if (null == m.get(target)) {
					continue;
				}
				System.out.println("input=" + i + " target=" + target + " targetSign=" + m.get(target));
			}
		}
	}

}

output:

input=0 target=[2,2] targetSign=9
input=0 target=[1,1] targetSign=5
input=1 target=[2,1] targetSign=8
input=1 target=[1,2] targetSign=6
input=2 target=[2,2] targetSign=9
input=2 target=[2,0] targetSign=7
input=3 target=[2,1] targetSign=8
input=3 target=[1,0] targetSign=4
input=4 target=[2,2] targetSign=9
input=4 target=[0,2] targetSign=3
input=5 target=[3,0] targetSign=0
input=6 target=[2,0] targetSign=7
input=6 target=[0,0] targetSign=1
input=7 target=[1,2] targetSign=6
input=7 target=[0,1] targetSign=2
input=8 target=[0,0] targetSign=1
input=8 target=[0,2] targetSign=3
input=9 target=[3,0] targetSign=0
input=9 target=[1,0] targetSign=4
input=9 target=[0,1] targetSign=2

- radobenc September 18, 2018 | Flag Reply


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