Problem of the Day -- Spiral Line

Anonymous - 10 years, 5 months ago

I did it :D.. was a harder one tbh.. nvm here is a haskell solution

spiral :: Int -> IO()
spiral x = printList $ spiral' x '*'



printList :: [String] -> IO ()
printList [] = putStrLn ""
printList (x:xs) = putStrLn x >> printList xs


spiral' :: Int -> Char -> [String]
spiral' i c
    | i <= 0 = []
    | i < 3 = [fill]
    | otherwise = fill:(final++[fill])
        where
            fill = [c | y <- [1..i]]
            next = correct rec
            rec = spiral' (i-2) o
            correct = map (([c] ++) . (++ [c]))
            correctFst = o:(tail fst')
            fst' = head next
            rest = tail next
            final = (correctFst) : rest
            o = if c == '*' then '.' else '*'

print list ist just there to show the printed list

now i can finally go to bed :D

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mf - 10 years, 5 months ago

another Haskell solution

module Main where
import Data.List (intersperse)

type Dimension = (Int,Int)
type Array = (Dimension, Int -> Int -> Char)
type ArrayTransformer = Array -> Array

main :: IO ()
main = putStrLn $ renderArray $ spiral 11

spiral :: Int -> Array
spiral 1 = base
spiral n = addLine . rot90 . addCorner $ spiral (n-1)

base :: Array
base = ((1,1),fn)
  where
     fn 1 1 = '*'
     fn l c = error $ show ("basefun out of Range",(l,c))

addCorner :: ArrayTransformer
addCorner ((lines,cols),fn) = ((lines,cols+1),fn')
  where
     fn' 1 1 = '*'
     fn' _ 1 = '.'
     fn' l c = fn l (c -1)

addLine :: ArrayTransformer
addLine ((lines,cols),fn) = ((lines+1,cols),fn')
  where
     fn' 1 _ = '*'
     fn' l c = fn (l-1) c

rot90 :: ArrayTransformer
rot90 ((lines,cols),fn) = ((cols,lines),fn')
  where
    fn' l c =  fn (lines-c+1) l

renderArray :: Array -> String
renderArray ((lines,cols),fn) = concat $ intersperse "\n" spiralLines
  where
    spiralLines :: [String]
    spiralLines = map makeLine [1..lines]
    makeLine :: Int -> String
    makeLine l = map (fn l) [1.. cols]

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David - 10 years, 5 months ago

I have spent way too much time messing around with this...

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David - 10 years, 4 months ago

I haven't touched this in most of the past week. I think I'll just post the crap I have at this point. No debug cleanup even.

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#define true 1
#define false 0
#define debug 1

#define Uint32  unsigned int

#define hDirIndex 0
#define vDirIndex 1

//These are to follow the convention of the spiral, not of a coordinate system
//[0][x] for horizontal direction
//[1][x] for vertical direction
signed char dir[2][4] = {{1,0,-1,0},
                            {0,1,0,-1}};

void spiralMove(int* hIndexIn, int* vIndexIn, int direction, int steps) {
    *hIndexIn += dir[hDirIndex][direction] * steps;
    *vIndexIn += dir[vDirIndex][direction] * steps;
    return;
}

bool edgeCheck(/*hIndex, vIndex, direction, size*/)
{
    //check vertical against direction
    //check horizontal against direction

    return true;
}

bool lineCheck()
{
    return true;
}

void spiralLine(int x) {
    char outputLine[x];
    char spiralMatrix[x][x];    //(vertical)(horizontal)
    bool spiralOn = false;
    char currentDir = 0;
    int currentVertIndex = 1;
    int currentHoriIndex = 0;
    int topBound = 0, rightBound = x, bottomBound = x, leftBound = 0;

    //Generate the "empty" array
    for(int verticalIndex = 0; verticalIndex < x; verticalIndex++) {
        for(int horizontalIndex = 0; horizontalIndex < x; horizontalIndex++) {
            spiralMatrix[verticalIndex][horizontalIndex] = '*';
        }
    }
    //Create the actual spiral
    if(x > 2) {
        spiralOn = true;
        spiralMatrix[currentVertIndex][currentHoriIndex] = '.';
    }
    else {
        return;
    }
    int failsafe = 0;
    while(spiralOn) {
        while((currentHoriIndex + 2 < x) & (spiralMatrix[currentVertIndex+2*dir[vDirIndex][currentDir]][currentHoriIndex+2*dir[hDirIndex][currentDir]] != '.') & spiralOn)  {  //Go right
            //TODO: check that we are inside the last spiral
            printf("%i, %i\n", currentHoriIndex, currentVertIndex);
            currentHoriIndex += 1;
            spiralMatrix[currentVertIndex][currentHoriIndex] = '.';
        }
        if(currentVertIndex + 2 < x || (spiralMatrix[currentVertIndex+dir[vDirIndex][currentDir]][currentHoriIndex+dir[hDirIndex][currentDir]] != '.')) {
            //TODO: check that we are inside the last spiral
            currentDir += 1;
        }
        else {
            printf("Debug: Break should end the loop\n");
            spiralOn = false;
            break;
        }
        while((currentVertIndex + 2 < x) & (spiralMatrix[currentVertIndex+2*dir[vDirIndex][currentDir]][currentHoriIndex+2*dir[hDirIndex][currentDir]] != '.') & spiralOn) {  //Go down
            //TODO: check that we are inside the last spiral
            printf("%i, %i\n", currentHoriIndex, currentVertIndex);
            currentVertIndex += 1;
            spiralMatrix[currentVertIndex][currentHoriIndex] = '.';
        }
        if(currentHoriIndex - 2 > 0 || (spiralMatrix[currentVertIndex+dir[vDirIndex][currentDir]][currentHoriIndex+dir[hDirIndex][currentDir]] != '.')) {
            //TODO: check that we are inside the last spiral
            currentDir += 1;
        }
        else {
            printf("Debug: Break should end the loop\n");
            spiralOn = false;
            break;
        }
        while((currentHoriIndex - 2 >= 0) & (spiralMatrix[currentVertIndex+2*dir[vDirIndex][currentDir]][currentHoriIndex+2*dir[hDirIndex][currentDir]] != '.') & spiralOn) {  //Go left
            printf("%i, %i\n", currentHoriIndex, currentVertIndex);
            currentHoriIndex -= 1;
            spiralMatrix[currentVertIndex][currentHoriIndex] = '.';
        }
        if(currentVertIndex - 2 > 0 || (spiralMatrix[currentVertIndex+dir[vDirIndex][currentDir]][currentHoriIndex+dir[hDirIndex][currentDir]] != '.')) {
            currentDir += 1;
        }
        else {
            printf("Debug: Break should end the loop\n");
            spiralOn = false;
            break;
        }
        while((currentVertIndex - 2 >= 0) & (spiralMatrix[currentVertIndex+2*dir[vDirIndex][currentDir]][currentHoriIndex+2*dir[hDirIndex][currentDir]] != '.') & spiralOn) {  //Go up
            printf("%i, %i\n", currentHoriIndex, currentVertIndex);
            currentVertIndex -= 1;
            spiralMatrix[currentVertIndex][currentHoriIndex] = '.';
        }
        if(currentHoriIndex + 2 < x || (spiralMatrix[currentVertIndex+dir[vDirIndex][currentDir]][currentHoriIndex+dir[hDirIndex][currentDir]] != '.')) {
            currentDir += 1;
            currentDir %= 4;
        }
        else {
            printf("Debug: Break should end the loop\n");
            spiralOn = false;
            break;
        }
        //check if we continue
        if(failsafe++ == 5)
        {
            printf("Debug: We hit the failsafe\n");
            spiralOn = false;   //At the moment I just want to make sure I exit the while loop
        }
    }
    for(int verticalIndex = 0; verticalIndex < x; verticalIndex++) {
        for(int horizontalIndex = 0; horizontalIndex < x; horizontalIndex++) {
            outputLine[horizontalIndex] = spiralMatrix[verticalIndex][horizontalIndex];
        }
#if debug
        printf("%s\n", outputLine);
#endif
    }
}

int main(void) {
    spiralLine(11);
    return 0;
}

It has a but with the last turn being right next to a previous line if the size is inconvenient. I had intended to make a more generic function for advancing in the current direction to save on if/else cases, but got busy.

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Problem of the Day
A new programming or logic puzzle every Mon-Fri

Spiral Line

Comments:

Problem of the Day A new programming or logic puzzle every Mon-Fri

Spiral Line

Comments:

Problem of the Day
A new programming or logic puzzle every Mon-Fri