Poj 3984 Maze problem (breadth-first BFS)

Basic breadth-first search.

Import Java. util. using list; import Java. util. queue; import Java. util. extends; public class main {public static void main (string... ARGs) {main = new main (); main. input (); main. process ();} private void input () {for (INT I = 0; I <5; I ++) for (Int J = 0; j <5; j ++) {maze [I] [J] = cin. nextint () ;}} private void process () {open = new vertex list <node> (); node start = new node (0, 0); start. pre = NULL; open. add (start ); Visit [0] [0] = true; node parentnode; node nextopen; while (! Open. isempty () {parentnode = open. peek (); open. remove (); // traverse the subnode for (INT I = 0; I <4; I ++) {// upper if (I = 0) {If (parentnode. X = 0) // No continue above; else if (maze [parentnode. x-1] [parentnode. y] = 1) // The above is the wall continue; else {nextopen = new node (parentnode. x-1, parentnode. y) ;}}// else if (I = 1) {If (parentnode. X = 4) continue; else if (maze [parentnode. X + 1] [parentnode. y] = 1) continue; else {nextopen = new node (PAR Entnode. X + 1, parentnode. y) ;}}// left else if (I = 2) {If (parentnode. y = 0) continue; else if (maze [parentnode. x] [parentnode. y-1] = 1) continue; else {nextopen = new node (parentnode. x, parentnode. y-1) ;}/// right else {If (parentnode. y = 4) continue; else if (maze [parentnode. x] [parentnode. Y + 1] = 1) continue; else {nextopen = new node (parentnode. x, parentnode. Y + 1) ;}} nextopen. pre = parentnode; If (nextopen. X = 4 & Amp; nextopen. Y = 4) {// print (nextopen);} If (! Visit [nextopen. x] [nextopen. y]) {visit [nextopen. x] [nextopen. y] = true; open. add (nextopen) ;}}} private void print (node) {If (node. pre! = NULL) print (node. PRE); system. out. println ("(" + node. X + "," + node. Y + ")");} private partition CIN = new partition (system. in); Private int [] [] maze = new int [5] [5]; private queue <node> open; private Boolean visit [] [] = new Boolean [5] [5];} class node {public node (int x, int y) {This. X = x; this. y = y;} public node () {} public int X; Public int y; Public node pre ;}

The General extended search process adds the close table and checks whether repeated search is performed using the hash table:

Package COM. xujin; import Java. util. hashset; import Java. util. using list; import Java. util. queue; import Java. util. extends; public class main {public static void main (string... ARGs) {main = new main (); main. input (); main. process ();} private void input () {for (INT I = 0; I <5; I ++) for (Int J = 0; j <5; j ++) {maze [I] [J] = cin. nextint () ;}} private void process () {node start = new node (0, 0); start. pre = NULL; o Pen. Add (start); node parentnode; node nextopen; label: While (! Open. isempty () {parentnode = open. peek (); close. add (parentnode); open. remove (); // traverse the subnode for (INT I = 0; I <4; I ++) {// upper if (I = 0) {If (parentnode. X = 0) // No continue above; else if (maze [parentnode. x-1] [parentnode. y] = 1) // The above is the wall continue; else {nextopen = new node (parentnode. x-1, parentnode. y) ;}}// else if (I = 1) {If (parentnode. X = 4) continue; else if (maze [parentnode. X + 1] [parentnode. y] = 1) continue; else {n Extopen = new node (parentnode. X + 1, parentnode. y) ;}}// left else if (I = 2) {If (parentnode. y = 0) continue; else if (maze [parentnode. x] [parentnode. y-1] = 1) continue; else {nextopen = new node (parentnode. x, parentnode. y-1) ;}/// right else {If (parentnode. y = 4) continue; else if (maze [parentnode. x] [parentnode. Y + 1] = 1) continue; else {nextopen = new node (parentnode. x, parentnode. Y + 1) ;}} nextopen. pre = parentn Ode; If (nextopen. x = 4 & nextopen. Y = 4) {// print (nextopen); break label;} If (! Close. Contains (nextopen) {open. Add (nextopen) ;}}} private void print (node) {If (node. Pre! = NULL) print (node. PRE); system. out. println ("(" + node. X + "," + node. Y + ")");} private partition CIN = new partition (system. in); Private int [] [] maze = new int [5] [5]; private queue <node> open = new queue list <node> ();; private hashset <node> close = new hashset <node> ();} class node {public node (int x, int y) {This. X = x; this. y = y;} public node () {} public int hashcode () {return x * 10 + Y;} public Boolean equals (Object node) {If (this. hashcode () = node. hashcode () return true; return false;} public int X; Public int y; Public node pre ;}