The lost Cow

Problems and Contests
#1

Question

My Solution:

#include <iostream>

using namespace std;

int main()
{
	int x , y;
	cin >> x >> y;// Taking input x and y
	int arr[3];
	int counter = 0; //declaring an integer counter
	int answer = 0;
	while(x < y) //if x is less than y x and y go into the while loop
	{
		counter++; // incrementing counter to calculate the iterations in the while loop
		arr[0] = x + 1;
		if(arr[0] == y)
		{
			answer = counter*(abs(arr[1] - arr[0]) + abs(arr[2] - arr[1])) + abs(arr[0] - x); // this is to find the distance travelled 
			cout << answer;
			break;
		}
		arr[1] = x - 2;
		if(arr[1] == y)
		{
			answer = counter*(abs(arr[1] - arr[0]) + abs(arr[2] - arr[1])) + abs(arr[1] - arr[0]);
			cout << answer;
			break;
		}
		arr[2] = x + 4; 
		if(arr[2] == y)
		{
			answer = counter*(abs(arr[1] - arr[0]) + abs(arr[2] - arr[2]));
			break;
		}
	}
}

this does not give any output… :frowning:

I also doubt if I have understood the question correctly.

#2

Could you please comment your code so we know what it actually does?

#3

I edited it with comment :slight_smile:
Could please tell me how to approach this question?

#4

isn’t there an editorial?

#5

Maybe they’re trying to figure it out on their own with just a little nudge in the right direction.

#6

Uhmm can anybody help me?
What I thought:

John starts
1.position x on number line

2.position x-2 on number line

  1. position x + 4 on number line

This goes on till x is equal to y

When x is equal to y,
My program then counts the distance covered

What is wrong with my algorithm or in my code/?

#7

When x is exactly equal to y? What if y is say, 3?

#8

\text{I have written most of the code...uhm can you please tell me once why} x = 3 and y = 6 \text{gives use output} 9?

#9

We first go to 4, 1, then 7.
3 -> 4 = 1 unit
4 -> 1 = 3 units
1 -> 6 = 5 units
Total is 9 units of distance

#10

Could you pls elaborate it?

#11

My C++ Code:

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
  ifstream fin("lostcow.in");
  ofstream fout("lostcow.out");
  int x , y;
  fin >> x >> y;
  int distance = 0;
  int counter = 0;
  while(x != y)
  {
    counter++;
    if(counter > 1)
    {
      x++;
    }
    if(x + 1 == y)
    {
      distance++;
      fout << distance;
      break;
    }
    distance++;
    if(x - 2 == y)
    {
      distance += 2;
      fout << distance;
      break;
    }
    distance += 2;
    if(x + 4 == y)
    {
      distance += 4;
      fout << distance;
      break;
    }
    distance += 4;
  } 
}
#12

I’m not sure how I would elaborate further…

#13

I mean what we do after we get 4, 1 and 7

#14

What do you mean? We simply output the total distance travelled before Bessie is found.

#15

I am confused In this part

#16

What are you confused about?

#17

How did you get this bold thing below?

3 -> 4
4 -> 1
1 -> 6

#18

I mean, first we go from x to x+1, then from x to x-2, so 3 - 2 = 1
Then we go from x to x + 4, so 3 + 4 = 7
However, 6 is in that range, so we stop at 6.

1 Like
#19

oh ok thanks! I misunderstood the question :slight_smile:

#20

I used the method you told…this is the code I wrote but it is not giving output:

#include <iostream>
#include <fstream>

using namespace std;

int main()
{
    ifstream fin("lostcow.in");
    ofstream fout("lostcow.out");
    int x , y;
    fin >> x >> y;
    int distance = 0;
    do
    {
        distance++;
        if(x + 1 == y)
        {
            fout << distance;
            break;
        }
        distance += 2;
        if(x - 2 == y)
        {
            fout << distance;
            break;
        }
        distance += 4;
        if(x + 4 == y)
        {
            fout << distance;
            break;
        }
        x = x + 4;
    }while(x != y);

    return 0;
}