Submission #1068730

#	Time	Username	Problem	Language	Result	Execution time	Memory
1068730		vjudge1	Naval battle (CEOI24_battle)	C++17	76 / 100	478 ms	49800 KiB

Main

#include <bits/stdc++.h>
#define int long long

using namespace std;

int collision(int x1, int y1, char c1, int x2, int y2, char c2) {
    if(c1 == c2) return -1;
    if((c2 == 'N' && c1 == 'S') or (c2 == 'W' && c1 == 'E')) {
        swap(x1, x2);
        swap(y1, y2);
        swap(c1, c2);
    }
    if(c1 == 'N' && c2 == 'S') {
        if(x1 != x2 or y1 < y2) return -1;
        return (y1 - y2)/2;
    }
    if(c1 == 'W' && c2 == 'E') {
        if(y1 != y2 or x1 < x2) return -1;
        return (x1 - x2)/2;
    }
    int X = abs(x1 - x2), Y = abs(y1 - y2);
    if(X != Y) return -1;
    if(c1 == 'E' or c1 == 'W') {
        swap(x1, x2);
        swap(y1, y2);
        swap(c1, c2);
    }
    if(c1 == 'N' && (y1 - Y) != y2) return -1;
    if(c1 == 'S' && (y1 + Y) != y2) return -1;
    if(c2 == 'W' && (x2 - X) != x1) return -1;
    if(c2 == 'E' && (x2 + X) != x1) return -1;
    return X;
}

bool cmp(pair<int,pair<int,int>>x, pair<int,pair<int,int>>y) {
    return x.first < y.first;
}

void solve() {
    int n;
    cin >> n;
    int x[n], y[n];
    char c[n];
    for(int i=0; i<n; ++i) {
        cin >> x[i] >> y[i] >> c[i];
    }
    if(n <= 5000) {
        vector<pair<int,pair<int,int>>>v;
        for(int i=0; i<n; ++i) {
            for(int j = i+1; j<n; ++j) {
                int X = collision(x[i], y[i], c[i], x[j], y[j], c[j]);
                if(X != -1) v.push_back({X, {i, j}});
            }
        }
        sort(v.begin(), v.end(), cmp);
        vector<int>taken(n, -1);
        for(int i=0; i<v.size(); ++i) {
            int first = v[i].second.first, second = v[i].second.second;
            if((taken[first] == v[i].first or taken[first] == -1) && (taken[second] == v[i].first or taken[second] == -1)) {
                taken[first] = v[i].first;
                taken[second] = v[i].first;
            }
        }
        for(int i=0; i<n; ++i) {
            if(taken[i] == -1) cout << i+1 << endl;
        }
        return;
    }
    // either south or east
    vector<vector<pair<int,int>>>v(n);
    map<int,int>m;
    int cnt = 1;
    for(int i=0; i<n; ++i) {
        int sum = x[i] + y[i];
        if(!m[sum]) {
            m[sum] = cnt;
            ++cnt;
        }
        v[m[sum]-1].push_back({y[i], i});
    }
    vector<int>ans;
    for(int i=0; i<cnt; ++i) {
        stack<int>s;
        sort(v[i].begin(), v[i].end());
        for(pair<int,int>p: v[i]) {
            if(c[p.second] == 'S') {
                s.push(p.second);
                continue;
            }
            if(s.empty()) ans.push_back(p.second);
            else s.pop();
        }
        while(!s.empty()) {
            int cur = s.top();
            s.pop();
            ans.push_back(cur);
        }
    }
    for(int i: ans) cout << i+1 << endl;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    int t = 1;
    while(t--) solve();

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:57:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, std::pair<long long int, long long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |         for(int i=0; i<v.size(); ++i) {
      |                      ~^~~~~~~~~

• 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