Submission #1095650

#	Time	Username	Problem	Language	Result	Execution time	Memory
1095650		vjudge1	Naval battle (CEOI24_battle)	C++17	100 / 100	616 ms	82940 KiB

Main

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

using pic = pair<int, char>;
using pii = pair<int, int>;
using node = tuple<int, int, int>;
const int N = 2e5 + 10;

int n, x[N], y[N], fc[N][4], nxt[8][N][4];
char d[N];

bool crash[N];

int f(char c) {
    const static string s = "NSWE"s;
    for(int i = 0; i < 4; i ++)
        if(c == s[i]) return i;
    return -1;
}

int jmpNxt(int d, int u, int p) {
    return crash[u] ? nxt[d][u][p] = jmpNxt(d, nxt[d][u][p], p) : u;
}

vector<int> cv[4];

int collide(int i, int j) {
    if(d[i] == d[j]) return -1;
    if(x[i] == x[j]) {
        if(y[i] < y[j] && d[i] == 'S' && d[j] == 'N') return (y[j] - y[i]) / 2;
        if(y[i] > y[j] && d[j] == 'S' && d[i] == 'N') return (y[i] - y[j]) / 2;
        return -1;
    }else if(y[i] == y[j]) {
        if(x[i] < x[j] && d[i] == 'E' && d[j] == 'W') return (x[j] - x[i]) / 2;
        if(x[j] < x[i] && d[j] == 'E' && d[i] == 'W') return (x[i] - x[j]) / 2;
        return -1;
    }else if(x[i] + y[i] == x[j] + y[j]) {
        if(x[i] > x[j] && d[i] == 'S' && d[j] == 'E') return x[i] - x[j];
        if(x[i] > x[j] && d[i] == 'W' && d[j] == 'N') return x[i] - x[j];
        if(x[j] > x[i] && d[j] == 'S' && d[i] == 'E') return x[j] - x[i];
        if(x[j] > x[i] && d[j] == 'W' && d[i] == 'N') return x[j] - x[i];
        return -1;
    }else if(x[i] - y[i] == x[j] - y[j]) {
        if(x[i] > x[j] && d[i] == 'N' && d[j] == 'E') return x[i] - x[j];
        if(x[i] > x[j] && d[i] == 'W' && d[j] == 'S') return x[i] - x[j];
        if(x[j] > x[i] && d[j] == 'N' && d[i] == 'E') return x[j] - x[i];
        if(x[j] > x[i] && d[j] == 'W' && d[i] == 'S') return x[j] - x[i];
        return -1;
    }
    return -1;
}

priority_queue<node, vector<node>, greater<node> > pq;

int getD[8][4];

void findCollide(int u) {
    if(crash[u]) return;
    int t = INT_MAX, tar = -1;
    for(int i = 0; i < 8; i ++)
        for(int j = 0; j < 4; j ++) {
            int v = jmpNxt(i, nxt[i][u][j], j);
            if(v != 0) {
                int x = collide(u, v);
                if(x != -1 && x < t) {
                    t = x;
                    tar = v;
                }
            }
        }
    if(t < INT_MAX) pq.emplace(t, u, tar);
    
}

vector<pii> mp[4][N];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    cin >> n;
    for(int i = 1; i <= n; i ++) {
        cin >> x[i] >> y[i] >> d[i];
        cv[0].push_back(x[i]);
        cv[1].push_back(y[i]);
        cv[2].push_back(x[i] + y[i]);
        cv[3].push_back(x[i] - y[i]);
    }

    for(int i = 0; i < 4; i ++) {
        sort(cv[i].begin(), cv[i].end());
        cv[i].erase(unique(cv[i].begin(), cv[i].end()), cv[i].end());
    }

    for(int i = 1; i <= n; i ++) {
        fc[i][0] = lower_bound(cv[0].begin(), cv[0].end(), x[i]) - cv[0].begin();
        fc[i][1] = lower_bound(cv[1].begin(), cv[1].end(), y[i]) - cv[1].begin();
        fc[i][2] = lower_bound(cv[2].begin(), cv[2].end(), x[i] + y[i]) - cv[2].begin();
        fc[i][3] = lower_bound(cv[3].begin(), cv[3].end(), x[i] - y[i]) - cv[3].begin();

        mp[0][fc[i][0]].emplace_back(fc[i][1], i);
        mp[1][fc[i][1]].emplace_back(fc[i][0], i);
        mp[2][fc[i][2]].emplace_back(fc[i][0], i);
        mp[3][fc[i][3]].emplace_back(fc[i][0], i);
    }

    for(int i = 0; i < 4; i ++)
        for(int j = 0; j < cv[i].size(); j ++) {
            sort(mp[i][j].begin(), mp[i][j].end());
            int tmp[4] = {0};
            for(auto [x, p] : mp[i][j]) {
                memcpy(nxt[i][p], tmp, sizeof tmp);
                tmp[f(d[p])] = p;
            }
            reverse(mp[i][j].begin(), mp[i][j].end());
            memset(tmp, 0, sizeof tmp);
            for(auto [x, p] : mp[i][j]) {
                memcpy(nxt[i ^ 4][p], tmp, sizeof tmp);
                tmp[f(d[p])] = p;
            }
        }

    for(int i = 1; i <= n; i ++)
        findCollide(i);
    
    while(pq.size()) {
        auto [t, u, v] = pq.top();
        pq.pop();
        if(crash[u] || crash[v]) {
            findCollide(u);
            continue;
        }
        vector<int> w{u};
        while(pq.size() && get<0>(pq.top()) == t) {
            auto [it, iu, iv] = pq.top();
            pq.pop();

            if(crash[iu] || crash[iv]) {
                findCollide(iu);
                continue;
            }
            w.emplace_back(iu);
        }

        for(int i : w) {
            crash[i] = true;
        }
    }

    for(int i = 1; i <= n; i ++)
        if(!crash[i]) cout << i << "\n";
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:108:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  108 |         for(int j = 0; j < cv[i].size(); j ++) {
      |                        ~~^~~~~~~~~~~~~~

• 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: 24 / 24