Given a square chessboard of N x N size, the position of Knight and position of a target is given. We need to find out minimum steps a Knight will take to reach the target position. - Codeprg

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Saturday, 11 July 2020

Given a square chessboard of N x N size, the position of Knight and position of a target is given. We need to find out minimum steps a Knight will take to reach the target position.

find out minimum steps a Knight will take to reach the target position.
find out minimum steps a Knight will take to reach the target position.

Given a square chessboard of N x N size, the position of Knight and position of a target is given. We need to find out the minimum steps a Knight will take to reach the target position.

Output:
Print the minimum steps the Knight will take to reach the target position.

For Input:
5
3
1 3
1 2
2
2 1
2 1
3
3 3
2 1
4
2 2
1 3
5
1 3
1 5
Your Output is:
3
0
1
2
2

#include <bits/stdc++.h>
#include<tuple>
using namespace std;

int main(){
int t;
cin>>t;

while(t--)
{
    int n,m,x,y,l,p=1,k=0;
    cin>>n;
    cin>>x>>y;
    cin>>l>>m;
  //create queue with tuple taking index and count
    queue< tuple<int,int,int> > q;
//push origin index into queue
    q.push(make_tuple(l,m,0));

    int a[n+1][n+1];
    a[l][m]=1;//origin is visited by assign 1
    memset(a,0,sizeof(a));
//if not possible return 1 i.e p=1;
    while(!q.empty())
    {
        // retrive the value from tuple which front of queue and pop
       l=get<0>(q.front());
       m=get<1>(q.front());
       k=get<2>(q.front());
      
        q.pop();
      
       if(l==x&&m==y)
        {    p=k;
            break;
            
        }
        ++k;
 //there are possible 8 way for every position
// push every possible path with satisfied condition and mark as visited
        if(l-1>0&&m+2<=n&&a[l-1][m+2]==0)
        {
            
            q.push(make_tuple(l-1,m+2,k));
            a[l-1][m+2]=1;
        }
        
        if(l+1<=n&&m+2<=n&&a[l+1][m+2]==0)
        {
           
            q.push(make_tuple(l+1,m+2,k));
            a[l+1][m+2]=1;
        }
        
        if(l-1>0&&m-2>0&&a[l-1][m-2]==0)
        {
            
            q.push(make_tuple(l-1,m-2,k));
            a[l-1][m-2]=1;
        }
        
         if(l+1<=n&&m-2>0&&a[l+1][m-2]==0)
        {
           
            q.push(make_tuple(l+1,m-2,k));
            a[l+1][m-2]=1;
        }
        
         if(l-2>0&&m+1<=n&&a[l-2][m+1]==0)
        {
            q.push(make_tuple(l-2,m+1,k));
            a[l-2][m+1]=0;
        }
        
         if(l-2>0&&m-1>0&&a[l-2][m-1]==0)
        {
           
            q.push(make_tuple(l-2,m-1,k));
            a[l-2][m-1]=1;
        }
        
        if(l+2<=n&&m+1<=n&&a[l+2][m+1]==0)
        {
           
            q.push(make_tuple(l+2,m+1,k));
            a[l+2][m+1]=1;
        }
        
         if(l+2<=n&&m-1>0&&a[l+2][m-1]==0)
        {
          
            q.push(make_tuple(l+2,m-1,k));
            a[l+2][m-1]=1;
        }
          
       }
   cout<<p<<endl;
    
}
return 0;
}