# A solution using pairs and BFS

#1

int Solution::knight(int A, int B, int C, int D, int E, int F) {
vector<vector> vec(A+1, vector (B+1, -1));
queue<pair<int,int>>q;
pair<int,int>temp;
q.push(make_pair(C,D));
vec[C][D]=0;
int ret=0;
while(!q.empty())
{
temp=q.front();
int x=temp.first;
int y=temp.second;
q.pop();
if(x==E&&y==F)
return vec[x][y];
if(x+1<=A&&y+2<=B&&vec[x+1][y+2]==-1)
{
q.push(make_pair(x+1,y+2));
vec[x+1][y+2]=vec[x][y]+1;
}
if(x+1<=A&&y-2>0&&vec[x+1][y-2]==-1)
{
q.push(make_pair(x+1,y-2));
vec[x+1][y-2]=vec[x][y]+1;

``````        }
if(x+2<=A&&y-1>0&&vec[x+2][y-1]==-1)
{
q.push(make_pair(x+2,y-1));
vec[x+2][y-1]=vec[x][y]+1;
}
if(x+2<=A&&y+1<=B&&vec[x+2][y+1]==-1)
{
q.push(make_pair(x+2,y+1));
vec[x+2][y+1]=vec[x][y]+1;
}
if(x-1>0&&y+2<=B&&vec[x-1][y+2]==-1)
{
q.push(make_pair(x-1,y+2));
vec[x-1][y+2]=vec[x][y]+1;
}
if(x-1>0&&y-2>0&&vec[x-1][y-2]==-1)
{
q.push(make_pair(x-1,y-2));
vec[x-1][y-2]=vec[x][y]+1;

}
if(x-2>0&&y-1>0&&vec[x-2][y-1]==-1)
{
q.push(make_pair(x-2,y-1));
vec[x-2][y-1]=vec[x][y]+1;
}
if(x-2>0&&y+1<=B&&vec[x-2][y+1]==-1)
{
q.push(make_pair(x-2,y+1));
vec[x-2][y+1]=vec[x][y]+1;
}
}
return -1;
``````

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