The Doppelgänger
Problem
Read the years, one at a time. A year can occur twice in a row. Print the duplicate years.
Solution 1
The register int is initially zero. Assume this to be the case and read input
into the register reg only. We print only if two consecutive values from input
are the same. This solution does not use a loop.
reg = input; // Read the year from input.
check int = reg; // Are both values the same?
jump if true: print; // If so, go to "print".
jump to: end; // Go to "end".
print: // The "print" branch.
output = int; // Print the duplicate year.
end: // The "end" branch.
int = reg; // Set current year to latest year.
Solution 2
Similar to Solution 1, but we use a loop. This solution is optimal, according to the game.
loop: // Start of "loop".
int = reg; // Set current year to latest year.
reg = input; // Read a year from input.
check int = reg; // Are two year values the same?
jump if false: loop; // If not, go to "loop".
output = int; // Print the duplicate year.
Solution 3
Similar to Solution 2, but we do not use an explicit loop. This solution is optimal, according to the game.
reg = input; // Read the year from input.
check int = reg; // Are both values the same?
jump if false: end; // If not, go to "end".
output = int; // Print the duplicate year.
end: // The "end" branch.
int = reg; // Set current year to latest year.