/* Author: LukArToDo Created: 15.march 2018 Bugs: unknown Description: The code solve the puzzle known as Zebra Puzzle. (https://en.wikipedia.org/wiki/Zebra_Puzzle) 🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸 👉 Note: for best view on mobile 📱, set landscape view. 🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸🔸 🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷🔷 ZEBRA PUZZLE (from 1962.year) The Zebra Puzzle is a logic puzzle said to be invented by Albert Einstein (but who knows), and Wikipedia says that only 2% of the world population is able to solve it (what is obviously questionable now 😁). Here’s how it goes: The puzzle consists of five different-colored houses in a row, each lived in by a resident of a different nationality. Each resident owns a different pet, prefers a different drink, and smokes a different brand of cigarettes than the others. You’re given 1⃣5⃣ other facts: ⤵️ 👉1.There are five houses. 👉2.The Englishman lives in the red house. 👉3.The Spaniard owns the dog. 👉4.Coffee is drunk in the green house. 👉5.The Ukrainian drinks tea. 👉6.The green house is immediately to the right of the ivory house (to your right as you stand facing the row of five houses). 👉7.The Old Gold smoker owns snails. 👉8.Kools are smoked in the yellow house. 👉9.Milk is drunk in the middle house. 👉10.The Norwegian lives in the first house. 👉11.The man who smokes Chesterfields lives in the house next to the man with the fox. 👉12.Kools are smoked in a house next to the house where the horse is kept. 👉13.The Lucky Strike smoker drinks orange juice. 👉14.The Japanese smokes Parliaments. 👉15.The Norwegian lives next to the blue house. To solve the puzzle, find: ❓ 1. Which man likes to drink water ❓ 2. Which man owns a zebra */ public class ZebraPuzzle{ static String[] Colors={"Red","Green","Ivory","Yellow","Blue"}, Nations={"English","Spaniard","Ukrainian","Norwegian","Japanese"}, Animals={"Dog","Snails","Fox","Horse","Zebra"}, Drinks={"Tea","Coffee","Milk","Juice","Water"}, Smokes={"OldGold","Kools","Chesterfields","LuckyStrike","Parliaments"}; static int[][] HousesAllComb=new int[120][5]; // [n!][n] static int count=0; public static void main(String...Zb){ int[] perm=new int[5]; for(int i=0; i<5; i++) perm[i]=i; allPerm(perm,0,perm.length); System.out.println(fillHouses()? "":"There is no solution found"); } static void allPerm(int[]perm,int startIndex,int endIndex){ if(startIndex==endIndex){ for(int i=0; i0; } static boolean check(int x1,int x2,int y1,int y2){ for(int i=0;i<5;i++) if(HousesAllComb[x1][i]==y1) return HousesAllComb[x2][i] ==y2; return false; } static boolean checkLeft(int x1,int x2,int y1,int y2){ for(int i=0;i<4;i++) if(HousesAllComb[x1][i]==y1) return HousesAllComb[x2][i+1] ==y2; return false; } static boolean checkRight(int x1,int x2,int y1,int y2){ for (int i=1;i<5;i++) if (HousesAllComb[x1][i]==y1) return HousesAllComb[x2][i-1] ==y2; return false; } static boolean checkNeighbor(int x1,int x2,int y1,int y2){ return checkLeft(x1,x2,y1,y2) || checkRight(x1,x2,y1,y2); } static void displaySolution(int C,int N,int A,int D,int S){ String owner="", drinker=""; System.out.println("Note: if you testing code on mobile device turn to landscape view to see the table properly.\n"); System.out.println("House Color Nation Animal Drink Smokes"); System.out.println("===== | ======= | ========= | ====== | ====== | ==========="); for(int i=0;i<5;i++){ System.out.printf("%3d | %-6s | %-9s | %-6s | %-6s | %-11s\n", i + 1, Colors[HousesAllComb[C][i]], Nations[HousesAllComb[N][i]], Animals[HousesAllComb[A][i]], Drinks[HousesAllComb[D][i]], Smokes[HousesAllComb[S][i]]); if(Animals[HousesAllComb[A][i]]=="Zebra") owner=Nations[HousesAllComb [N][i]]; if(Drinks[HousesAllComb[D][i]]=="Water") drinker=Nations[HousesAllComb [N][i]]; } System.out.println("\n\nThe " + drinker+" drinks the water."); System.out.println("\nThe " + owner+" owns the zebra."); } }

ZEBRA PUZZLE (from 1962)