Thread: How to learn everything

"How to learn everything?"

Cure the disease by solving an actual problem.

Wolves vs. Sheep Puzzle

Since your brain needs something to do: My idea of putting sheep on the main diagonal and them putting wolves a knight's move away hasn't worked and I've been trying to put a fifth wolf in for too long. It's impossible, prove me wrong.

Originally Posted by whiteflags

Wolves vs. Sheep Puzzle
It's impossible, prove me wrong.

It's impossible, here is proof by exhaustive search.

Code:

#include <stdio.h>

void MarkDirty(bool* , int);
int CountClean(bool*);

int main(){

	bool Dirty[25];

	for(int a = 0;a<25;a++){
		for(int b = 0;b<25;b++){
			for(int c = 0;c<25;c++){
				for(int d = 0;d<25;d++){
					for(int e = 0;e<25;e++){
						if(a!=b && a!=c && a!=d && a!=e && b!=c && b!=d && b!=e && c!=d && c!=e && d!=e){
							// every wolf is in a unique location
							for(int x = 0;x<25;x++) Dirty[x] = false;
							MarkDirty(Dirty , a);
							MarkDirty(Dirty , b);
							MarkDirty(Dirty , c);
							MarkDirty(Dirty , d);
							MarkDirty(Dirty , e);

							if(CountClean(Dirty) > 2){
								printf("Solution at %d %d %d %d %d\n" , a , b , c , d , e);
								}
							}
						}
					}
				}
			}
		}

	return 0;
	}

void MarkDirty(bool* Dirty, int Cell){
	int Row = Cell - (Cell % 5);
	
	for(int x = Row;x<Row + 5;x++) Dirty[x] = true;
	for(int x = 0;x<5;x++) Dirty[(Cell + (x*5)) % 25] = true;
	for(int x = 0;x<5;x++) Dirty[(Cell + (x*5) + x) % 25] = true;
	for(int x = 0;x<5;x++) Dirty[(Cell + (x*5) - x) % 25] = true;
	
	return;
	}

int CountClean(bool* Dirty){
	int Count = 0;

	for(int x = 0;x<25;x++){
		if(!Dirty[x]) Count++;
		}

	return Count;
	}