Submission #1103784

#	Time	Username	Problem	Language	Result	Execution time	Memory
1103784		TVSown	Naval battle (CEOI24_battle)	C++17	76 / 100	364 ms	33600 KiB

Main

///*** Sown_Vipro ***///
/// ->GIAI BA QUOC GIA<- ///

#include<bits/stdc++.h>
using namespace std;
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
#define F first
#define S second
#define pb push_back
#define pi pair<int, int>
#define pii pair<int, pair<int, int> >
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define REP(i, a, b) for(int i = a; i >= b; --i)
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
#define szz(s) int(s.size())
const int N = 2e5 + 5, MAX = 1e6, oo = 1e9 + 5, MOD = 1e9 + 7;
int n;
int d[N];
struct node{
    int x, y, t, id;
} p[N];


namespace sub1{
    struct query{
        int i, j, d;
    };
    vector<query> q;

    pi Find(node a, node b){
        int l = a.y, r = (a.t == 1 ? oo : 0);
        if(l > r) swap(l, r);
    //    cout << l << " " << r << "\n";
        if(l > b.y || b.y > r) return {-1, -1};
        l = b.x, r = (b.t == 3 ? oo : 0);
        if(l > r) swap(l, r);
    //    cout << l << " " << r << "\n";
        if(l > a.x || a.x > r) return {-1, -1};
        return {a.x, b.y};
    }

    void check(node a, node b, int i, int j){
        if(a.t == b.t){
            if(a.x == b.x && a.y == b.y) q.pb({i, j, 0});
            return;
        }

        if(a.t > b.t) swap(a, b);
        if(a.t == 1 && b.t == 2){
            if(a.x == b.x && a.y <= b.y) q.pb({i, j, (b.y - a.y) / 2});
            return;
        }
        if(a.t == 3 && b.t == 4){
    //        cout << a.x << " " << a.y << " " << b.x << " " << b.y << "\n";
            if(a.y == b.y && a.x <= b.x) q.pb({i, j, (b.x - a.x) / 2});
            return;
        }
        pi g = Find(a, b);
        if(g.F == -1) return;

        int x, y;
        if(b.t == 3){
            x = g.F - b.x;
        }
        if(b.t == 4){
            x = b.x - g.F;
        }
        if(a.t == 1){
            y = g.S - a.y;
        }
        if(a.t == 2){
            y = a.y - g.S;
        }
    //    cout << g.F << " " << g.S << " " << b.x << " " << a.y << " " << x << " " << y << "\n";
        if(x == y){
            q.pb({i, j, x});
        }
    }

    bool cmp(query a, query b){
        return a.d < b.d;
    }

    void solve(){
        FOR(i, 1, n){
            FOR(j, 1, i - 1){
                check(p[i], p[j], i, j);
            }
        }

        sort(q.begin(), q.end(), cmp);
        stack<pi> st;
        for(int i = 0; i < szz(q);){
            int x = q[i].d;

            while(i < szz(q) && x == q[i].d){
    //            cout << q[i].i << " " << q[i].j << " " << x << " " << d[q[i].i] << " " << d[q[i].j] << "\n";
                if(!d[q[i].i] && !d[q[i].j]){
                    st.push({q[i].i, q[i].j});
                }
                ++i;
            }
            while(szz(st)){
                d[st.top().F] = d[st.top().S] = 1;
                st.pop();
            }
        }
        FOR(i, 1, n) if(!d[i]) cout << i << "\n";
    }
}

namespace sub2{
    vector<int> q[N];
    vector<int> tmp;
    int f(int x){
        return lower_bound(tmp.begin(), tmp.end(), x) - tmp.begin();
    }

    bool cmp(node a, node b){
        if(a.x == b.x) return a.t > b.t;
        return a.x < b.x;
    }

    void solve(){
        FOR(i, 1, n){
            tmp.pb(p[i].x + p[i].y);
            p[i].id = i;
        }
        sort(tmp.begin(), tmp.end());
        sort(p + 1, p + 1 + n, cmp);

        FOR(i, 1, n){
            int F = f(p[i].x + p[i].y);
            if(p[i].t == 1){
                if(q[F].size()){
                    d[p[i].id] = d[p[q[F].back()].id] = 1; q[F].pop_back();
                }
            }else{
                q[F].pb(i);
            }
        }
        FOR(i, 1, n) if(!d[i]) cout << i << "\n";
    }
}

void solve(){
    cin >> n;
    FOR(i, 1, n){
        char t;
        cin >> p[i].x >> p[i].y >> t;
        if(t == 'S') p[i].t = 1;
        if(t == 'N') p[i].t = 2;
        if(t == 'E') p[i].t = 3;
        if(t == 'W') p[i].t = 4;
    }
    if(n <= 5000) sub1::solve();
    else sub2::solve();
//    sub2::solve();
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
//    inp("in.txt");
//    out("out.txt");
    int t = 1;
//    cin >> t;
    while(t--){
        solve();
    }
}

Compilation message (stderr)

Main.cpp: In function 'void sub1::check(node, node, int, int)':
Main.cpp:78:9: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   78 |         if(x == y){
      |         ^~
Main.cpp:79:17: warning: 'x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   79 |             q.pb({i, j, x});
      |             ~~~~^~~~~~~~~~~

• 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: 30 / 30
• Subtask 7: 0 / 24