Interview Questions-maze questions-breadth-first search-queue

// Maze problem --- Search for breadth first ----- queue # include <stdio. h ># include <queue >#include <iostream> using namespace STD; # define max_row 5 # define max_col 5 struct point {int row; int Col ;}; queue <point> S; int maze [max_row] [max_col] = {, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0}; void print_maze () {for (INT I = 0; I <max_row; ++ I) {for (Int J = 0; j <max_col; ++ J) {printf ("% d", maze [I] [J]);} printf ("\ n ");} printf ("********************* * ** \ N ");} struct point predecessor [max_row] [max_col] ={{-1,-1 },{-1,-1 }, {-1,-1}, {-1,-1}, {-1,-1 }}, {-1,-1}, {-1, -1}, {-1,-1}, {-1,-1}, {-1,-1 }}, {-1,-1 }, {-1,-1}, {-1,-1}, {-1,-1}, {-1,-1 }}, {-1, -1}, {-1,-1}, {-1,-1}, {-1,-1}, {-1,-1 }}, {-1,-1}, {-1,-1}, {-1,-1}, {-1,-1}, {-1, -1 }}; void visit (INT row, int Col, struct point pre) {point visit_point = {row, Col}; maze [row] [col] = 2; predecessor [row] [col] = pre; S. push (visit _ Point) ;}int main () {point P = {0, 0}; maze [p. row] [p. col] = 2; S. push (p); While (! S. empty () {P = S. front (); S. pop (); // arrive at the destination if (P. row = MAX_ROW-1 & P. col = MAX_COL-1) {break;} // move down if (P. row + 1 <max_row & maze [p. row + 1] [p. col] = 0) {visit (P. row + 1, p. col, P);} // move it to the right if (P. col + 1 <max_col & maze [p. row] [p. col + 1] = 0) {visit (P. row, P. col + 1, P);} // move up if (P. col-1> = 0 & maze [p. row] [p. col-1] = 0) {visit (P. row, P. col-1, P);} // move it to the left if (P. row-1> = 0 & maze [p. row-1] [p. col] = 0) {visit (P. row-1, p. col, P);} print _ Maze ();} If (P. row = MAX_ROW-1 & P. col = MAX_COL-1) {printf ("(% d, % d) \ n", p. row, P. COL); While (predecessor [p. row] [p. col]. row! =-1) {P = predecessor [p. row] [p. col]; printf ("(% d, % d) \ n", p. row, P. COL) ;}} else {cout <"no path" <Endl ;}return 0 ;}

 

Running result:

 

2 2 0 0 0
2 0 0 1 0
0 1 0 0 0
0 0 0 0 0
0 0 0 1 0
************************
2 2 0 0 0
2 2 0 1 0
2 1 0 0 0
0 0 0 0 0
0 0 0 1 0
************************
2 2 2 0 0
2 2 0 1 0
2 1 0 0 0
0 0 0 0 0
0 0 0 1 0
************************
2 2 2 0 0
2 2 0 1 0
2 1 0 0 0
2 0 0 0 0
0 0 0 1 0
************************
2 2 2 0 0
2 2 2 1 0
2 1 0 0 0
2 0 0 0 0
0 0 0 1 0
************************
2 2 2 2 0
2 2 2 1 0
2 1 0 0 0
2 0 0 0 0
0 0 0 1 0
************************
2 2 2 2 0
2 2 2 1 0
2 1 0 0 0
2 2 0 0 0
2 0 0 1 0
************************
2 2 2 2 0
2 2 2 1 0
2 1 2 0 0
2 2 0 0 0
2 0 0 1 0
************************
2 2 2 2
2 2 2 1 0
2 1 2 0 0
2 2 0 0 0
2 0 0 1 0
************************
2 2 2 2
2 2 2 1 0
2 1 2 0 0
2 2 0 0 0
2 2 0 1 0
************************
2 2 2 2
2 2 2 1 0
2 1 2 0 0
2 2 2 0 0
2 2 0 1 0
************************
2 2 2 2
2 2 2 1 0
2 1 2 2 0
2 2 2 0 0
2 2 0 1 0
************************
2 2 2 2
2 2 2 1 2
2 1 2 2 0
2 2 2 0 0
2 2 0 1 0
************************
2 2 2 2
2 2 2 1 2
2 1 2 2 0
2 2 2 0 0
2 2 2 1 0
************************
2 2 2 2
2 2 2 1 2
2 1 2 2 0
2 2 2 2 0
2 2 2 1 0
************************
2 2 2 2
2 2 2 1 2
2 1 2 2 2
2 2 2 2 0
2 2 2 1 0
************************
2 2 2 2
2 2 2 1 2
2 1 2 2 2
2 2 2 2 0
2 2 2 1 0
************************
2 2 2 2
2 2 2 1 2
2 1 2 2 2
2 2 2 2 0
2 2 2 1 0
************************
2 2 2 2
2 2 2 1 2
2 1 2 2 2
2 2 2 2
2 2 2 1 0
************************
2 2 2 2
2 2 2 1 2
2 1 2 2 2
2 2 2 2
2 2 2 1 0
************************
2 2 2 2
2 2 2 1 2
2 1 2 2 2
2 2 2 2
2 2 2 1 2
************************
(4, 4)
(3, 4)
(3, 3)
(3, 2)
(3, 1)
(3, 0)
(2, 0)
(1, 0)
(0, 0)
Press any key to continue...

 

 

 

A 0-1 matrix is used to simulate a maze. 1 indicates an obstacle and 0 indicates a channel. 2 indicates the accessed data.

Require entering the maze from the entrance in the upper left corner, and exit the maze from the lower right corner. This article simulates the process of searching for the exit. In the future, I will improve this program so that it can output all feasible paths.

Some questions require that you only go to the right or down. You only need to remove the left and up conditions in this question.