thelongeststring

Problem

Find the longest string.

27. thelongeststring, Comet 64

Solution 1

Read a string from input and determine its length. If the length of the new string is less than the length of the longest string so far, then read the next string. Otherwise, the length of the new string is at least the length of the longest string so far. Set the longest string (so far) to the newly read string and read the next string. If there are no more strings from input, print the longest string. Use the register reg to hold the length of the longest string so far.

check input = null;      // Any more strings?
jump if true: print;     // If no more, go to "print".
jump if false: compare;  // Otherwise, go to "compare".
compare:                 // The "compare" branch.
    str = input;         // Read an input string.
    int = str.length;    // How many characters in the string.
    check reg < int;     // New string has more characters?
    jump if false: end;  // If not, go to "end".
    reg = int;           // Otherwise, note the larger length.
    switch str;          // Store the new string.
    jump to: end;        // Go to "end".
print:                   // The "print" branch.
    switch str;          // Retrieve the longest string.
    output = str;        // Print the longest string.
end:                     // End of program.

Solution 2

Similar to Solution 1. However, we remove a jump instruction and a label. We also add an explicit loop. This solution is optimal, according to the game.

loop:
    check input = null;   // Any more strings?
    jump if true: print;  // If not, go to "print".
    str = input;          // Read the input string.
    int = str.length;     // How many characters in the string.
    check reg < int;      // New string has more characters?
    jump if false: loop;  // If not, go to "end".
    reg = int;            // Otherwise, note larger length.
    switch str;           // Store the new string.
    jump to: loop;        // Go to "loop".
print:                    // The "print" branch.
    switch str;           // Retrieve the longest string.
    output = str;         // Print the longest string.