Submission #1059423

#	Time	Username	Problem	Language	Result	Execution time	Memory
1059423		Trent	Fountain Parks (IOI21_parks)	C++17	5 / 100	120 ms	27324 KiB

parks

#include "parks.h"
#include "bits/stdc++.h"
using namespace std;
#define forR(i, x) for(int i = 0; i < (x); ++i)
#define REP(i, a, b) for(int i = (a); i < (b); ++i)
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<bool> vb;
typedef set<int> si;
struct pii{int a, b;};
bool operator <(pii a, pii b) {return a.a < b.a || a.a == b.a && a.b < b.b;}
const int MD = 2e5 + 10;

bool conn(int n, vi& u, vi& v) {
    vvi adj(n);
    forR(i, u.size()) {
        adj[u[i]].push_back(v[i]);
        adj[v[i]].push_back(u[i]);
    }
    vb vis(n);
    vi dfs = {0};
    while(!dfs.empty()) {
        int cur = dfs.back(); dfs.pop_back();
        if(!vis[cur]) {
            vis[cur] = true;
            for(int i : adj[cur]) if(!vis[i]) {
                dfs.push_back(i);
            }
        }
    }
    forR(i, n) if(!vis[i]) return false;
    return true;
}
int construct_roads(std::vector<int> x, std::vector<int> y) {
    int n = x.size();
    map<pii, int> ci;
    forR(i, n) ci[{x[i], y[i]}] = i;
    vi u, v, a, b;
    for(auto [co, id] : ci) {
        if(ci.count({co.a, co.b + 2})) {
            u.push_back(id);
            v.push_back(ci[{co.a, co.b+2}]);
            a.push_back(co.a - 1);
            b.push_back(co.b + 1);
        }
    }
    for(int y = 2; y < MD; y += 2) {
        if(ci.count({4, y}) && ci.count({2, y})) {
            u.push_back(ci[{2, y}]);
            v.push_back(ci[{4, y}]);
            a.push_back(3);
            b.push_back(y + 1);
        }
    }
    if(conn(n, u, v)) {
        build(u, v, a, b);
        return 1;
    }
    return 0;
}

Compilation message (stderr)

parks.cpp: In function 'bool operator<(pii, pii)':
parks.cpp:12:63: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   12 | bool operator <(pii a, pii b) {return a.a < b.a || a.a == b.a && a.b < b.b;}
      |                                                    ~~~~~~~~~~~^~~~~~~~~~~~
parks.cpp: In function 'bool conn(int, vi&, vi&)':
parks.cpp:4:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    4 | #define forR(i, x) for(int i = 0; i < (x); ++i)
      |                                     ^
parks.cpp:17:5: note: in expansion of macro 'forR'
   17 |     forR(i, u.size()) {
      |     ^~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30