Submission #1134341

#	Time	Username	Problem	Language	Result	Execution time	Memory
1134341		ReLice	Naval battle (CEOI24_battle)	C++20	46 / 100	298 ms	25256 KiB

Main

#include <bits/stdc++.h>
#define ll int
#define ld double
#define pb push_back
#define pf push_front
#define ins insert
#define fr first
#define sc second
#define endl "\n"
#define ar array
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()

using namespace std;
void start(){ios_base::sync_with_stdio(NULL);cin.tie(nullptr);cout.tie(nullptr);}

void solve() {
    ll i, j;

    ll n;
    cin>>n;

    ll x[n + 1], y[n + 1];
    ll d[n + 1];

    vector<ll> vv;

    for(i=1;i<=n;i++){
        char ch;
        cin>>x[i]>>y[i]>>ch;

        if(ch == 'N') d[i] = 0;
        if(ch == 'S') d[i] = 1;
        if(ch == 'W') d[i] = 2;
        if(ch == 'E') d[i] = 3;

        vv.pb(x[i] + y[i]);
    }

    if(n <= 5000){
        vector<ar<ll, 3>> v;

        for(i=1;i<=n;i++){
            for(j=i + 1;j<=n;j++){
                if(d[i] == d[j]) continue;

                if(d[i] > d[j]) swap(i, j);

                if(d[i] == 0 && d[j] == 1 && x[i] == x[j] && y[j] < y[i]){
                    v.pb({(y[i] - y[j]) / 2, i, j});
                }
                if(d[i] == 2 && d[j] == 3 && y[i] == y[j] && x[i] > x[j]){
                    v.pb({(x[i] - x[j]) / 2, i, j});
                }

                if(d[i] <= 1 && d[j] >= 2){
                    bool f = 0;

                    if(d[i] == 0 && d[j] == 2 && x[j] - x[i] == y[i] - y[j] && x[j] > x[i]) f = 1;
                    if(d[i] == 0 && d[j] == 3 && x[i] - x[j] == y[i] - y[j] && x[i] > x[j]) f = 1;
                    if(d[i] == 1 && d[j] == 2 && x[j] - x[i] == y[j] - y[i] && x[j] > x[i]) f = 1;
                    if(d[i] == 1 && d[j] == 3 && x[i] - x[j] == y[j] - y[i] && x[i] > x[j]) f = 1;

                    if(f){
                        v.pb({abs(x[i] - x[j]), i, j});
                    }
                }

                if(i > j) swap(i, j);
            }
        }

        vector<bool> f(n + 1, true);

        sort(rall(v));

        while(v.size()){
            vector<ll> vv;

            ll x = v.back()[0];

            while(v.size() && v.back()[0] == x){
                i = v.back()[1], j = v.back()[2];

                v.pop_back();

                if(f[i] && f[j]){
                    vv.pb(i);
                    vv.pb(j);
                }
            }

            for(auto i : vv){
                f[i] = 0;
            }
        }

        for(i=1;i<=n;i++) {
            if(f[i]) cout<<i<<endl;
        }
        return;
    }

    sort(all(vv));
    vv.erase(unique(all(vv)), vv.end());

    map<ll,ll> pos;
    for(i=0;i<vv.size();i++){
        pos[vv[i]] = i;
    }

    vector<vector<pair<ll,ll>>> v(vv.size()), h(vv.size());

    for(i=1;i<=n;i++){
        if(d[i] == 1) v[pos[x[i] + y[i]]].pb({x[i], i});
        else h[pos[x[i] + y[i]]].pb({x[i], i});
    }

    for(i=0;i<vv.size();i++) sort(all(vv));

    vector<ar<ll, 3>> ev;

    for(i=0;i<vv.size();i++){
        ll x = 0, y = 0;
        while(x < v[i].size()){

            while(y < h[i].size() && v[i][x].fr > h[i][y].fr) y++;

            ev.pb({h[i][y].fr - v[i][x].fr, v[i][x].sc, h[i][y].sc});

            x++;
        }
    }

    vector<bool> f(n + 1, true);

    sort(rall(ev));

    while(ev.size()){
        vector<ll> vv;

        ll x = ev.back()[0];

        while(ev.size() && ev.back()[0] == x){
            i = ev.back()[1], j = ev.back()[2];

            ev.pop_back();

            if(f[i] && f[j]){
                vv.pb(i);
                vv.pb(j);
            }
        }

        for(auto i : vv){
            f[i] = 0;
        }
    }

    for(i=1;i<=n;i++) {
        if(f[i]) cout<<i<<endl;
    }


}

signed main(){
    start();

    ll t = 1;
    //cin>>t;

    while(t--) solve();
}

/*


*/

• Subtask 0: 0 / 0
• Subtask 1: 6 / 6
• Subtask 2: 12 / 12
• Subtask 3: 8 / 8
• Subtask 4: 11 / 11
• Subtask 5: 9 / 9
• Subtask 6: 0 / 30
• Subtask 7: 0 / 24