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 <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;
}
Solution in C++ :
In C ++ :
#include <bits/stdc++.h>
using namespace std ;
std::vector<long long int> g[1000007];
long long int dis[10001];
bool visited[10001] ;
int main()
{
long long int n ;
cin >> n ;
string temp ;
std::vector<string> v;
queue<long long int> q;
for(long long int i=0;i<n;i++)
{
cin >> temp ;
v.push_back(temp) ;
}
long long int a,b,c,d,start,end,next,front;
cin >> a >> b >> c >> d ;
for(long long int i=0;i<n;i++)
{
for(long long int j=0;j<n;j++)
{
if(v[i][j]=='.')
{
start = i*n+j ;
for(long long int k=i-1;k>=0;k--)
{
if(v[k][j]=='.')
{
end = n*k+j ;
g[start].push_back(end) ;
}
else
{
break ;
}
}
for(long long int k=i+1;k<n;k++)
{
if(v[k][j] == '.')
{
end = k*n + j;
g[start].push_back(end);
}
else
{
break;
}
}
for(long long int k=j-1;k>=0;k--)
{
if(v[i][k] == '.')
{
end = i*n+k;
g[start].push_back(end);
}
else
{
break;
}
}
for(long long int k=j+1;k<n;k++)
{
if(v[i][k]=='.')
{
end = i*n + k;
g[start].push_back(end);
}
else
{
break;
}
}
}
}
}
start = a*n+b;
q.push(start);
visited[start] = 1;
while(q.empty()==0)
{
front = q.front();
q.pop();
for(long long int i=0;i<g[front].size();i++)
{
next = g[front][i];
if(visited[next]==0)
{
visited[next] = 1;
dis[next] = dis[front]+1;
q.push(next);
}
}
}
cout<<dis[c*n+d] ;
return 0 ;
}
Solution in Java :
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 scan=new Scanner(System.in);
int n=scan.nextInt();
char[][] matrix=new char[n][n];
boolean[] visited=new boolean[n*n];
int[] parent=new int [n*n];
for(int i=0;i<n*n;i++)
{
parent[i]=-1;
}
for(int i=0;i<n;i++)
{
String pattern=scan.next();
for(int j=0;j<n;j++)
{
matrix[i][j]=pattern.charAt(j);
//System.out.print(matrix[i][j]);
}
//System.out.println();
}
int a=scan.nextInt();
int b=scan.nextInt();
int c=scan.nextInt();
int d=scan.nextInt();
int source=n*a+b;
int des=n*c+d;
LinkedList<Integer> list=new LinkedList<Integer>();
list.add(source);
while(list.size()>0)
{
int x=list.remove();
// System.out.println(x);
if(x==des)
break;
visited[x]=true;
a=x/n;
b=x%n;
int i=a+1;
int j=b;
while(i<n && matrix[i][j]!='X')
{
if(visited[n*i+j]==false)
{
list.add(n*i+j);
parent[n*i+j]=x;
visited[n*i+j]=true;
}
i++;
}
i=a-1;
j=b;
while(i>=0 && matrix[i][j]!='X')
{
if(visited[n*i+j]==false)
{
list.add(n*i+j);
parent[n*i+j]=x;
visited[n*i+j]=true;
}
i--;
}
i=a;
j=b+1;
while(j<n && matrix[i][j]!='X')
{
if(visited[n*i+j]==false)
{
list.add(n*i+j);
parent[n*i+j]=x;
visited[n*i+j]=true;
}
j++;
}
i=a;
j=b-1;
while(j>=0 && matrix[i][j]!='X')
{
if(visited[n*i+j]==false)
{
list.add(n*i+j);
parent[n*i+j]=x;
visited[n*i+j]=true;
}
j--;
}
}
int i=des;
int count=0;
while(parent[i]!=-1)
{
i=parent[i];
count++;
}
System.out.println(count);
}
}
Solution in Python :
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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