OTHER - Two robots, C++ (gcc)

OTHER - Two robots

Two robots land with their parachutes on an infinite one-dimensional number line. They both release their parachutes as soon as they land and start moving. They are allowed only to make use of the following functions.

I.                 moveLeft() // robot moves to left by 1 unit in 1 unit time

II.               moveRight() // robot moves to right by 1 unit in 1 unit time

III.              noOperation() // robot does not move and takes 1 unit time

IV.              onTopOfParachute() // returns true if the robot is standing on top of either of the parachute, else false

V.               didWeMeet() // returns true if the robot meets to the other robot, else false

Write a function in order to make the robots meet each other. Robots will be executing the same copy of this function.

// First idea from left to right

while (didWeMeet()) {
  distance = 1;

for (int i = 0; i < distance; ++i) {
    moveLeft();
    if (didWeMeet())
      return true;
  }

for (int i = 0; i < distance; ++i) {
    moveRight();
    if (didWeMeet())
      return true;
  }

// we are at on our parachute

for (int i = 0; i < distance; ++i) {
    moveRight();
    if (didWeMeet())
      return true;
  }

for (int i = 0; i < distance; ++i) {
    moveLeft();
    if (didWeMeet())
      return true;
  }

++distance;

}

=========================================================

while (didWeMeet()) {
  distance = 1;

for (int i = 0; i < distance; ++i) {
    moveLeft();
    if (didWeMeet())
      return true;

// we found the other robot's parachute
    if (onTopOfParachute())
      while (didWeMeet())
	moveLeft();
  }

for (int i = 0; i < distance; ++i) {
    moveRight();
    if (didWeMeet())
      return true;
  }

// we are at on our parachute

for (int i = 0; i < distance; ++i) {
    moveRight();
    if (didWeMeet())
      return true;

// we found the other robot's parachute
    if (onTopOfParachute())
      while (didWeMeet())
	moveRight();
  }

for (int i = 0; i < distance; ++i) {
    moveLeft();
    if (didWeMeet())
      return true;
  }

++distance;

}


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