The Lost Cow

Python:

1. Read x and y from your input

import math

sign = 1
movement = 1
total_distance = 0
while True:
    new_location = x + sign * movement

    # Case 1: FJ passes Bessie
    if (y > x and new_location >= y) or (y < x and new_location <= y):
        # FJ has passed Bessie
        total_distance = total_distance + math.abs(x-y)
        break

    # Case 2: FJ does not pass Bessie
    else:
        total_distance = total_distance + movement * 2

    sign = sign * (-1)
    movement = movement * 2

output the total_distance


C++/Java:

1. Read x and y from your input


int sign = 1;
int movement = 1;
int total_distance = 0;
while (true) {
    int new_location = x + sign * movment;

    // Case 1: FJ passes Bessie
    if (y > x && new_location >= y) || (y < x && new_location <= y) {
        // FJ has passed Bessie
        total_distance = total_distance + abs(x-y);
        break;
    }

    // Case 2: FJ does not pass Bessie
    else {
        total_distance = total_distance + movement * 2;
    }

    sign = sign * (-1);
    movement = movement * 2;
}

output the total_distance

// sign   =  1,-1, 1,-1, 1
// movment = 1, 2, 4, 8, 16, ...

x --> x+1 -> x --> x-2 -> x --> x+4 -> x --> x-8 -> x --> x+16 -> x -> y