Problem F
Snakes and Ladders

Snakes and Ladders

Write a program that plays the legendary board game, Snakes and Ladders.

The game is played on a board with exactly $100$ squares, numbered from $1$ to $100$.

The rules of the game are as follows:

• In each turn, a player rolls a die and moves forward by the same number of squares as indicated by the die.

• After having moved, if the player is located at the bottom of a ladder, the player moves up the ladder. If a player is instead located at the head of a snake, the player moves down to the tail of the snake.

• If a player rolls $6$, then that player gets to roll the die again. It doesn’t matter if the player just moved up a ladder or down a snake, they are still entitled to another roll.

• The player who is first to reach the last square wins.

• If a player is close to the last square and overshoots by rolling a number higher than required, then the player still moves to square $100$ and wins the game.

The starter code includes a main() function and a function named roll_die() that shall be used to simulate the rolling of a single $6$-sided die.

Input

First the program should prompt the user for $n$, the number of snakes and ladders on the board.

The second part of the input contains $n$ lines, where each line $i$ contains two integers $s_i$ and $e_i$, separated by a space, indicating which squares on the board are connected by snakes or ladders, where $s_i$ designates the starting square and $e_i$ the end square of a particular connection.

If $s_i > e_i$ then the pair is considered to be a snake, but if $e_i > s_i$ then it will be a ladder.

Lastly the program should prompt the user for two names, $p_1$ and $p_2$, the names of Player $1$ and Player $2$. The program then proceeds to play the game following the rules indicated above. Player $1$ starts the game.

In the tests $n$ will be restricted to $1 \le n \le 49$. It is guaranteed that no snake/ladder will overlap one another. The names $p_1$ and $p_2$ will be of length $1 \le |p_1|, |p_2| \le 10$.

Output

For each turn of the game the program should output the rolls and locations of the players as such:

• “{$p$} rolled {$r$} and is now at {$d$}.”

where $p$ is the name of the given player, $r$ is the number that came up on the die, and $d$ is the number of the destination square where the player ended up after moving according to the die. Additionally it should display one of these messages when players land on a start of a snake or a ladder:

• “Darn! A snake brought {$p$} down to square {$d'$}.”

• “Splendid! {$p$} climbed a ladder up to square {$d'$}.”

where $d'$ is the square the snake or ladder took the player to. When the game is over, the program should output

• “{$p$} won the game.”

9
21 75
30 60
7 18
67 30
85 94
89 60
50 75
11 26
52 16
Joseph
Donald

Joseph rolled 5 and is now at square 5.
Donald rolled 5 and is now at square 5.
Joseph rolled 6 and is now at square 11.
Splendid! Joseph climbed a ladder up to square 26.
Joseph rolled 3 and is now at square 29.
Donald rolled 5 and is now at square 10.
Joseph rolled 5 and is now at square 34.
Donald rolled 6 and is now at square 16.
Donald rolled 2 and is now at square 18.
Joseph rolled 3 and is now at square 37.
Donald rolled 4 and is now at square 22.
Joseph rolled 6 and is now at square 43.
Joseph rolled 3 and is now at square 46.
Donald rolled 3 and is now at square 25.
Joseph rolled 4 and is now at square 50.
Splendid! Joseph climbed a ladder up to square 75.
Donald rolled 6 and is now at square 31.
Donald rolled 2 and is now at square 33.
Joseph rolled 6 and is now at square 81.
Joseph rolled 3 and is now at square 84.
Donald rolled 1 and is now at square 34.
Joseph rolled 4 and is now at square 88.
Donald rolled 6 and is now at square 40.
Donald rolled 4 and is now at square 44.
Joseph rolled 1 and is now at square 89.
Darn! A snake brought Joseph down to square 60.
Donald rolled 5 and is now at square 49.
Joseph rolled 6 and is now at square 66.
Joseph rolled 6 and is now at square 72.
Joseph rolled 3 and is now at square 75.
Donald rolled 4 and is now at square 53.
Joseph rolled 4 and is now at square 79.
Donald rolled 6 and is now at square 59.
Donald rolled 3 and is now at square 62.
Joseph rolled 6 and is now at square 85.
Splendid! Joseph climbed a ladder up to square 94.
Joseph rolled 1 and is now at square 95.
Donald rolled 3 and is now at square 65.
Joseph rolled 5 and is now at square 100.
Joseph won the game.