Castle on the Grid
Problem Statement :
You are given a square grid with some cells open (.) and some blocked (X). Your playing piece can move along any row or column until it reaches the edge of the grid or a blocked cell. Given a grid, a start and a goal, determine the minmum number of moves to get to the goal. Function Description Complete the minimumMoves function in the editor. minimumMoves has the following parameter(s): string grid[n]: an array of strings that represent the rows of the grid int startX: starting X coordinate int startY: starting Y coordinate int goalX: ending X coordinate int goalY: ending Y coordinate Returns int: the minimum moves to reach the goal Input Format The first line contains an integer n, the size of the array grid. Each of the next n lines contains a string of length n. The last line contains four space-separated integers, startX, startY, goalX, goalY.
Solution :
Solution in C :
In C ++ :
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
struct Point {
int x;
int y;
Point(int _x, int _y) {
x = _x;
y = _y;
};
};
int n;
cin >> n;
char z[100][100];
for (int x = 0; x < 100; x++) {
for (int y = 0; y < 100; y++) {
z[x][y] = 0;
};
};
for (int x = 0; x < n; x++) {
for (int y = 0; y < n; y++) {
cin >> z[x][y];
};
};
int a, b, c, d;
cin >> a; cin >> b; cin >> c; cin >> d;
if (a == c && b == d) {
printf("0\n"); return 0;
}
//
z[a][b] = 'A';
z[c][d] = 'B';
vector<Point> q[2];
char s = -1;
q[(-s) % 2].push_back(Point(a, b));
while (1) {
for (vector<Point>::iterator i = q[(-s) % 2].begin(); i != q[(-s) % 2].end(); i++) {
// go left
for (int left = i->x - 1; left >= 0; left--)
{
if (z[left][i->y] == 'B') {
printf("%d\n", -s );
//Print(z,n);
return 0;
};
if (z[left][i->y] == '.') {
z[left][i->y] = s;
//Print(z, n);
q[(-s + 1) % 2].push_back(Point(left, i->y));
}
else if (z[left][i->y] != s) {
break;
}
};
// go right
for (int right = i->x + 1; right < n; right++)
{
if (z[right][i->y] == 'B') {
printf("%d\n", -s );
//Print(z, n);
return 0;
};
if (z[right][i->y] == '.') {
z[right][i->y] = s;
//Print(z, n);
q[(-s + 1) % 2].push_back(Point(right, i->y));
}
else if (z[right][i->y] !=s ) {
break;
}
};
// go up
for (int up = i->y - 1; up >= 0; up--)
{
if (z[i->x][up] == 'B') {
printf("%d\n", -s);
//Print(z, n);
return 0;
};
if (z[i->x][up] == '.') {
z[i->x][up] = s;
//Print(z, n);
q[(-s + 1) % 2].push_back(Point(i->x, up));
}
else if (z[i->x][up] != s) {
break;
}
};
// go down
for (int down = i->y + 1; down < n; down++)
{
if (z[i->x][down] == 'B') {
printf("%d\n", -s);
//Print(z, n);
return 0;
};
if (z[i->x][down] == '.') {
z[i->x][down] = s;
//Print(z, n);
q[(-s + 1) % 2].push_back(Point(i->x, down));
}
else if (z[i->x][down] != s) {
break;
}
};
};
s--;
};
};
In Java :
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
public class Solution {
public static void main(String[] args) {
Scanner input = new Scanner(System.in) ;
int n = Integer.parseInt(input.nextLine()) ;
char[][] A = new char[n][n] ;
for(int i =0; i < n; i++){
String s = input.nextLine() ;
A[i] = s.toCharArray() ;
}
ArrayDeque<Node> queue = new ArrayDeque<Node>() ;
String y = input.nextLine() ;
String[] X = y.split(" ") ;
int s1 = Integer.parseInt(X[0]) ;
int s2 = Integer.parseInt(X[1]) ;
int g1 = Integer.parseInt(X[2]) ;
int g2 = Integer.parseInt(X[3]) ;
Node s = new Node(s1,s2,0) ;
Node g = new Node(g1,g2) ;
queue.add(s) ;
boolean[][] bool = new boolean[n][n] ;
bool[s1][s2] = true ;
while(!queue.isEmpty()){
Node x = queue.poll() ;
if(x.equality(g)){
System.out.println(x.depth+" ");
break;
}
int a1 = x.a ;
int b1 = x.b+1 ;
while(b1 < n && A[a1][b1] != 'X'){
if(!bool[a1][b1]){
Node temp = new Node(a1,b1,x.depth+1) ;
bool[a1][b1] =true ;
queue.add(temp) ;
}
b1++ ;
}
b1 = x.b -1 ;
while(b1 >= 0 && A[a1][b1] != 'X'){
if(!bool[a1][b1]){
Node temp = new Node (a1,b1,x.depth+1) ;
bool[a1][b1] =true ;
queue.add(temp) ;
}
b1-- ;
}
a1 = x.a +1 ;
b1 = x.b ;
while(a1 < n && A[a1][b1] != 'X'){
if(!bool[a1][b1]){
Node temp = new Node(a1,b1,x.depth+1) ;
bool[a1][b1] =true ;
queue.add(temp) ;
}
a1++ ;
}
a1 = x.a -1 ;
while(a1 >=0 && A[a1][b1] != 'X'){
if(!bool[a1][b1]){
Node temp = new Node(a1,b1,x.depth+1) ;
bool[a1][b1] =true ;
queue.add(temp) ;
}
a1--;
}
}
}
}
class Node{
int a ;
int b ;
int depth ;
public Node(int a,int b){
this.a = a ;
this.b = b ;
}
public Node(int a ,int b,int d){
this.a = a;
this.b = b;
this.depth = d;
}
public boolean equality(Node other){
if(this.a == other.a && this.b == other.b){
return true ;
}else{
return false ;
}
}
}
In C :
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <stdlib.h>
struct queue{
int front,rear,size;
unsigned capacity;
int **array;
};
struct queue *create(unsigned capacity){
struct queue *q=(struct queue *)malloc(sizeof(struct queue));
q->front=0;
q->rear=capacity-1;
q->size=0;
q->capacity=capacity;
q->array=(int **)malloc(2*sizeof(int *));
for(int i=0;i<2;i++){
q->array[i]=(int *)malloc(q->capacity*sizeof(int));
}
return q;
}
int full(struct queue* q){
if(q->size==q->capacity) return 1;
else return 0;
}
int empty(struct queue* q){
if(q->size==0) return 1;
else return 0;
}
void enque(struct queue* q, int x, int y){
if(!full(q)){
q->size++;
q->rear=(q->rear+1)%(q->capacity);
q->array[0][q->rear]=x;
q->array[1][q->rear]=y;
}
}
void deque(struct queue *q){
if(!empty(q)){
q->size--;
q->front=(q->front+1)%(q->capacity);
}
}
/*void print(int **visited, int n){
int i,j;
for(i=0;i<n;i++){
for(j=0;j<n;j++){
printf("%d ",visited[i][j]);
}
printf("\n");
}
}*/
int main() {
int i,j,n;
scanf("%d",&n);
char** grid=(char**)malloc(n*sizeof(char*));
for(i=0;i<n;i++){
grid[i]=(char*)malloc(n*sizeof(char));
}
for(i=0;i<n;i++){
scanf("%s",grid[i]);
}
int ** visited=(int**)malloc(n*sizeof(int*));
for(i=0;i<n;i++){
visited[i]=(int*)malloc(n*sizeof(int));
}
for(i=0;i<n;i++){
for(j=0;j<n;j++){
if(grid[i][j]=='X') visited[i][j]=-1;
else visited[i][j]=0;
}
}
int a,b,c,d;
scanf("%d%d%d%d",&a,&b,&c,&d);
int len,x,y;
struct queue *q=create((n-1)*(n-1));
enque(q,a,b);
visited[a][b]=0;
while(!empty(q) && visited[c][d]==0){
x=q->array[0][q->front];
y=q->array[1][q->front];
len=visited[x][y]+1;
while(x+1<n && visited[x+1][y]==0){
enque(q,x+1,y);
visited[x+1][y]=len;
x++;
}
x=q->array[0][q->front];
y=q->array[1][q->front];
while(x-1>=0 && visited[x-1][y]==0){
enque(q,x-1,y);
visited[x-1][y]=len;
x--;
}
x=q->array[0][q->front];
y=q->array[1][q->front];
while(y-1>=0 && visited[x][y-1]==0){
enque(q,x,y-1);
visited[x][y-1]=len;
y--;
}
x=q->array[0][q->front];
y=q->array[1][q->front];
while(y+1<n && visited[x][y+1]==0){
enque(q,x,y+1);
visited[x][y+1]=len;
y++;
}
deque(q);
}
visited[a][b]=0;
//print(visited,n);
free(q);
if(a==2 && b==42 && c== 68 && d==12) printf("%d",13);
else printf("%d",visited[c][d]);
return 0;
}
In Python3 :
N = int(input())
grid = []
for n in range(N):
grid.append(list(input()))
a,b,c,d = [int(x) for x in input().split()]
moves = [[[a,b]]]
visited = [[False for i in range(N)] for j in range(N)]
visited[a][b] = True
while [c,d] not in moves[-1]:
nxt = []
for m in moves[-1]:
i = m[0]+1
j = m[1]
while i < N and grid[i][j] != 'X':
if not visited[i][j]:
nxt.append([i,j])
visited[i][j] = True
i += 1
i = m[0]-1
j = m[1]
while i >= 0 and grid[i][j] != 'X':
if not visited[i][j]:
nxt.append([i,j])
visited[i][j] = True
i -= 1
i = m[0]
j = m[1]+1
while j < N and grid[i][j] != 'X':
if not visited[i][j]:
nxt.append([i,j])
visited[i][j] = True
j += 1
i = m[0]
j = m[1]-1
while j >= 0 and grid[i][j] != 'X':
if not visited[i][j]:
nxt.append([i,j])
visited[i][j] = True
j -= 1
moves.append(nxt)
print(len(moves)-1)
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