Submission #212928

#	Time	Username	Problem	Language	Result	Execution time	Memory
212928		Blerargh	Tower Defense (CEOI19_towerdefense)	C++17	100 / 100	6 ms	512 KiB

towerdefense

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

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> ii;
typedef pair<ld,ld> id;

#define FOR(i, a, b) for(int i=(a); i<=(b); i++)
#define ROF(i, a, b) for(int i=(a); i>=(b); i--)
#define MEM(x, v) memset(x, v, sizeof(x))
#define FILL(x, n, v) fill(x, x+n, v);
#define ALL(x) x.begin(), x.end()
#define SORT(x) sort((x).begin(), (x).end())
#define CMPSORT(x, cp) sort((x).begin(), (x).end(), cp)
#define FAST ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

#define f first
#define s second
#define ins insert
#define e emplace
#define eb emplace_back
#define ef emplace_front
#define p push
#define pf push_front
#define pb push_back
#define mp make_pair
#define ub upper_bound
#define lb lower_bound
#define ft front
#define bk back
#define pp pop
#define ppb pop_back
#define ppf pop_front

#define db cout<<"YEET\n";
#define ct(x) cout<<x<<'\n';

const ll MOD = 1e9+7; //998244353
const ll MAXN = 2e5+5;
const ll INF = 1e18;
const ld PI = acos((ld)-1);

int main(){
    FAST
    ll sx, sy, ex, ey;
    cin >> sx >> sy >> ex >> ey;
    ll d;
    cin >> d;
    ll dist = abs(ey-sy) + abs(ex-sx);

    bool left;
    if (sx <= ex) left=1;
    else left=0;

    vector<ii> ans;

    if (dist > d || (d-dist)&1){
        cout << "impossible";
        return 0;
    } else if (abs(ex-sx)==1 && abs(ey-sy)==1) {
        if (d<=5 && d>=3){
            cout << "impossible";
            return 0;
        } else if (d!=2) {
            ll border = (d-6)/2;

            if (left) {
                ans.eb(sx+1,sy);
                ans.eb(sx,sy+1);
                ans.eb(sx,sy-1);

                FOR(i,1,border){
                    ans.eb(sx-i,sy+1);
                    ans.eb(sx-i,sy-1);
                }
            } else {
                ans.eb(sx-1,sy);
                ans.eb(sx,sy+1);
                ans.eb(sx,sy-1);

                FOR(i,1,border){
                    ans.eb(sx+i,sy+1);
                    ans.eb(sx+i,sy-1);
                }
            }
        }
    } else if (dist==1){
        if (d!=1) {
            cout << "impossible";
            return 0;
        }
    } else if (abs(ey-sy)<=1){
        ll border = (d-dist)/2 - 1;

        if (border!=-1){
            if (left){
                ans.eb(sx+1,sy);
                FOR(i,1,border){
                    ans.eb(sx+1,sy+i);
                    ans.eb(sx+1,sy-i);
                }
                if (abs(ey-sy)==1) {
                    ans.eb(sx+1,sy+border+1);
                    ans.eb(sx+1,sy-border-1);
                }
            } else {
                ans.eb(sx-1,sy);
                FOR(i,1,border){
                    ans.eb(sx-1,sy+i);
                    ans.eb(sx-1,sy-i);
                }
                if (abs(ey-sy)==1) {
                    ans.eb(sx-1,sy+border+1);
                    ans.eb(sx-1,sy-border-1);
                }
            }
        }
    } else {
        ll backtrack = (d-dist)/2;

        if (left){
            ans.eb(sx+1,sy-1);
            ans.eb(sx+1,sy);
            ans.eb(sx+1,sy+1);

            FOR(i,1,backtrack){
                ans.eb(sx-i+1, sy+1);
                ans.eb(sx-i+1, sy-1);
            }
        } else {
            ans.eb(sx-1,sy-1);
            ans.eb(sx-1,sy);
            ans.eb(sx-1,sy+1);

            FOR(i,1,backtrack){
                ans.eb(sx+i-1, sy+1);
                ans.eb(sx+i-1, sy-1);
            }
        }
    }

    cout << ans.size() << '\n';
    for (auto i : ans){
        cout << i.f << " " << i.s << '\n';
    }
}

• Subtask 1: 25 / 25
• Subtask 2: 28 / 28
• Subtask 3: 47 / 47