Submission #212490

#	Time	Username	Problem	Language	Result	Execution time	Memory
212490		kai824	Tower Defense (CEOI19_towerdefense)	C++17	100 / 100	5 ms	512 KiB

towerdefense

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

#define mp make_pair
#define pii pair<int,int>

pii p1,p2,d1,d2;

int32_t main(){
    ios_base::sync_with_stdio(false);cin.tie(0);
		int xs,ys,xe,ye,d,cur_d;
		cin>>xs>>ys>>xe>>ye>>d;
		cur_d=abs(xs-xe)+abs(ys-ye);
		if(cur_d==d){
			cout<<"0\n";
			return 0;
		}
		if(cur_d>d || ((d-cur_d)%2)!=0 || cur_d==1){
			cout<<"impossible\n";
			return 0;
		}
		if(cur_d<=1){//start spot same as end spot...
			cout<<"impossible\n";
			return 0;
		}else if(cur_d==2 && xs!=xe && ys!=ye){//diff column, diff row...
			if(d==4){
				cout<<"impossible\n";return 0;
			}
		}
		p1.first=xe;p1.second=ye;
		if(xs<xe)p1.first--;
		else if(xs>xe)p1.first++;
		if(ys<ye)p1.second--;
		else if(ys>ye)p1.second++;

		p2=p1;
		d1=d2=mp(0,0);
		if(xs<xe){
			if(ys==ye){
				d1.second=-1;
				d2.second=1;
			}else if(ys<ye){
				d1=mp(1,0);
				d2=mp(0,1);
			}else{
				d1=mp(1,0);
				d2=mp(0,-1);
			}
		}else if(xs==xe){
			d1=mp(1,0);
			d2=mp(-1,0);
		}else{
			if(ys==ye){
				d1.second=-1;
				d2.second=1;
			}else if(ys<ye){
				d1=mp(-1,0);
				d2=mp(0,1);
			}else{
				d1=mp(-1,0);
				d2=mp(0,-1);
			}
		}

		if(xs!=xe && ys!=ye){
			p1.first+=d1.first;
			p1.second+=d1.second;
			p2.first+=d2.first;
			p2.second+=d2.second;
		}
		vector<pii> turrets;
		while(cur_d<d){
			if(turrets.size()>10000){
				cout<<"impossible\n";
				return 0;
			}
			turrets.push_back(p1);
			if(p1!=p2)turrets.push_back(p2);
			if(cur_d==2 && xs!=xe && ys!=ye){//diff column, diff row...
				cur_d+=4;
			}else cur_d+=2;
			p1.first+=d1.first;
			p1.second+=d1.second;
			p2.first+=d2.first;
			p2.second+=d2.second;
		}
		if(turrets.size()>10000){
			cout<<"impossible\n";
			return 0;
		}
		cout<<turrets.size()<<'\n';
		for(int i=0;i<turrets.size();i++){
			cout<<turrets[i].first<<' '<<turrets[i].second<<'\n';
		}
    return 0;
}

Compilation message (stderr)

towerdefense.cpp: In function 'int32_t main()':
towerdefense.cpp:92:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<turrets.size();i++){
               ~^~~~~~~~~~~~~~~

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