CUBE-112: Golden Rectangle

#include <bits/stdc++.h>
using namespace std;
using pi=pair<int,int>;
using pii=pair<int,pi>;
char ar[1000][1000];
int f[16];
bool visited[16];
int n,m;
void p_ar(){
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            printf("%c",ar[i][j]);
        }
        printf("\n");
    }
}
int find_start(int i){
    if(i%4==0) return i;
    else if(i<=3) return 1;
    else if(i<=7) return 5;
    else if(i<=11) return 9;
    else return 13;
}
void fill_ar(int ui,int uj,int num){
    n=max(n,f[num]+ui-1);
    m=max(m,f[num]+uj-1);
    for(int i=ui;i<=f[num]+ui-1;i++){
        for(int j=uj;j<=f[num]+uj-1;j++){
            ar[i][j]=64+num;
        }
    }
}
int main(){

    int N;
    scanf("%d",&N);

    for(int i=1;i<=N;i++){
        if(i==1 or i==2) f[i]=1;
        else f[i]=f[i-1]+f[i-2];
    }

    int start;
    start=find_start(N);

    queue <pii> q;
    q.push({ start , {1,1} });
    while(q.size()>0){
        int ui,uj,num;
        num=q.front().first;
        ui=q.front().second.first;
        uj=q.front().second.second;
        q.pop();
        visited[num] = true;
        fill_ar(ui,uj,num);

        int vi,vj,v_num;
        if(num+1<=N and !visited[num+1]){
            v_num=num+1;

            if(num%4==1)
                q.push({v_num,{ui,uj+f[num]}});

            else if(num%4==3)
                q.push({v_num,{ui-f[num-1],uj-f[num+1]}});

            else if(num%4==2)
                q.push({v_num,{ui+f[num],uj-f[num-1]}});

        }
        if(num-1>=1 and !visited[num-1]){
            v_num=num-1;

            if(num%4==1)
                q.push({v_num,{ui+f[num],uj}});

            else if(num%4==0)
                q.push({v_num,{ui+f[num-2],uj+f[num]}});

            else if(num%4==3)
                q.push({v_num,{ui-f[num-1],uj+f[num-2]}});

            else if(num%4==2)
                q.push({v_num,{ui,uj-f[num-1]}});

        }
    }

    p_ar();

    return 0;
}
/*
EEEEE  FFFFFFFF
EEEEE  FFFFFFFF
EEEEE  FFFFFFFF
EEEEE  FFFFFFFF
EEEEE  FFFFFFFF
DDD AB FFFFFFFF
DDD CC FFFFFFFF
DDD CC FFFFFFFF
*/