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Submission #600088

# Submission time Handle Problem Language Result Execution time Memory
600088 2022-07-20T12:55:19 Z Valaki2 Fountain Parks (IOI21_parks) C++17
15 / 100
 1275 ms 219744 KB 
#include "parks.h"
#include <bits/stdc++.h>
using namespace std;

#define x X
#define y Y

#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define fi first
#define se second

const int maxn = 2e5;
const vector<pii > directions = {mp(-2, 0), mp(0, -2), mp(0, 2), mp(2, 0)};

bool check_possibility(int n, vector<int> x, vector<int> y) {
    unordered_map<int, unordered_map<int, bool> > m;
    unordered_map<int, unordered_map<int, int> > f;
    for(int i = 0; i < n; i++) {
        f[x[i]][y[i]] = i + 1;
    }
    queue<int> q;
    q.push(0);
    m[x[0]][y[0]] = true;
    int cnt = 0;
    while(!q.empty()) {
        int cur = q.front();
        q.pop();
        cnt++;
        for(pii dir : directions) {
            pii new_point = mp(x[cur] + dir.fi, y[cur] + dir.se);
            if(f[new_point.fi][new_point.se] && !m[new_point.fi][new_point.se]) {
                m[new_point.fi][new_point.se] = true;
                int new_id = f[new_point.fi][new_point.se] - 1;
                q.push(new_id);
            }
        }
    }
    return (cnt == n);
}

struct fountain {
    int x, y, id;
    fountain() : x(0), y(0), id(-1) {}
    fountain(int x_, int y_, int id_) :
        x(x_), y(y_), id(id_) {}
};

int n;
vector<fountain > points;
vector<int> x;
vector<int> y;
unordered_map<int, unordered_map<int, int> > fountain_at;

unordered_map<int, unordered_map<int, bool> > bench_at;
unordered_map<int, unordered_map<int, bool> > road_at;
vector<int> ans_u;
vector<int> ans_v;
vector<int> ans_a;
vector<int> ans_b;

void build_road_bench(int road_u, int road_v, pii bench_pos) {
    ans_u.pb(road_u);
    ans_v.pb(road_v);
    ans_a.pb(bench_pos.fi);
    ans_b.pb(bench_pos.se);
    bench_at[bench_pos.fi][bench_pos.se] = true;
    road_at[(points[road_u].x + points[road_v].x) / 2][(points[road_u].y + points[road_v].y) / 2] = true;
}

vector<pii> get_bench_locations_pii(pii a, pii b) {
    fountain f_a = fountain(a.fi, a.se, -1), f_b = fountain(b.fi, b.se, -1);
    if(f_a.x == f_b.x) {
        int new_y = (f_a.y + f_b.y) / 2;
        a = mp(f_a.x + 1, new_y), b = mp(f_a.x - 1, new_y);
    } else {
        int new_x = (f_a.x + f_b.x) / 2;
        a = mp(new_x, f_a.y + 1), b = mp(new_x, f_a.y - 1);
    }
    return {min(a, b), max(a, b)};
}

vector<pii> get_bench_locations(int a_idx, int b_idx) {
    fountain f_a = points[a_idx], f_b = points[b_idx];
    pii a, b;
    if(f_a.x == f_b.x) {
        int new_y = (f_a.y + f_b.y) / 2;
        a = mp(f_a.x + 1, new_y), b = mp(f_a.x - 1, new_y);
    } else {
        int new_x = (f_a.x + f_b.x) / 2;
        a = mp(new_x, f_a.y + 1), b = mp(new_x, f_a.y - 1);
    }
    return {min(a, b), max(a, b)};
}

int get_middle_of_intersection(int a_idx, int b_idx) {
    pii a = mp(points[a_idx].x, points[a_idx].y);
    pii b = mp(points[b_idx].x, points[b_idx].y);
    int cnt = 0;
    for(pii dir : directions) {
        pii nei = mp(a.fi + dir.fi, a.se + dir.se);
        if(fountain_at[nei.fi][nei.se]) {
            cnt++;
        }
    }
    if(cnt == 4) {
        return a_idx;
    }
    cnt = 0;
    for(pii dir : directions) {
        pii nei = mp(b.fi + dir.fi, b.se + dir.se);
        if(fountain_at[nei.fi][nei.se]) {
            cnt++;
        }
    }
    if(cnt == 4) {
        return b_idx;
    }
    return -1;
}

pii get_bench_when_in_intersection(int a_idx, int b_idx) {
    // a is the middle, b is a neighbour
    fountain a = points[a_idx], b = points[b_idx];
    if(b.x < a.x) {
        return mp(a.x - 1, a.y + 1);
    }
    if(b.y < a.y) {
        return mp(a.x - 1, a.y - 1);
    }
    if(b.y > a.y) {
        return mp(a.x + 1, a.y + 1);
    }
    if(b.x > a.x) {
        return mp(a.x + 1, a.y - 1);
    }
}

pii orig;
unordered_map<int, unordered_map<int, int> > not_bad;

bool bad_bench(pii bench, pii a, pii b) {
    int tmp = not_bad[bench.fi][bench.se];
    if(tmp == 1) {
        return false;
    }
    if(tmp == 2) {
        return true;
    }
    if(a > b) {
        swap(a, b);
    }
    vector<pii > v = {a, b};
    for(pii dir : directions) {
        pii other = mp(bench.fi + dir.fi, bench.se + dir.se);
        vector<pii> corners = get_bench_locations_pii(bench, other);
        if(corners != v) {
            if(fountain_at[corners[0].fi][corners[0].se] &&
                fountain_at[corners[1].fi][corners[1].se] &&
                //bench_at[other.fi][other.se] &&
                !road_at[(bench.fi + other.fi) / 2][(bench.se + other.se) / 2]) {
                if(other == orig) {
                    not_bad[bench.fi][bench.se] = 1;
                    return false;
                }
                if(bench_at[other.fi][other.se]) {
                    //not_bad[bench.fi][bench.se] = 2;
                    return true;
                } else {
                    bool res = bad_bench(other, corners[0], corners[1]);
                    if(res) {
                        //not_bad[bench.fi][bench.se] = 2;
                    } else {
                        not_bad[bench.fi][bench.se] = 1;
                    }
                    return res;
                }
            }
        }
    }
    not_bad[bench.fi][bench.se] = 1;
    return false;
}

void solve() {
    unordered_map<int, unordered_map<int, bool> > vis;
    queue<int> q;
    q.push(0);
    vis[x[0]][y[0]] = true;
    while(!q.empty()) {
        int cur = q.front();
        q.pop();
        for(pii dir : directions) {
            pii new_point = mp(x[cur] + dir.fi, y[cur] + dir.se);
            if(fountain_at[new_point.fi][new_point.se] && !vis[new_point.fi][new_point.se]) {
                vis[new_point.fi][new_point.se] = true;
                int new_id = fountain_at[new_point.fi][new_point.se] - 1;
                q.push(new_id);
                int mid = get_middle_of_intersection(cur, new_id);
                if(mid != -1) {
                    build_road_bench(cur, new_id, get_bench_when_in_intersection(mid, cur ^ new_id ^ mid));
                } else {
                    vector<pii> benches = get_bench_locations(cur, new_id);
                    orig = benches[0];
                    if(!bench_at[benches[0].fi][benches[0].se] && !bad_bench(benches[0], mp(points[cur].x, points[cur].y), mp(points[new_id].x, points[new_id].y))) {
                        build_road_bench(cur, new_id, benches[0]);
                    } else {
                        build_road_bench(cur, new_id, benches[1]);
                    }
                }
            }
        }
    }
    //
}

#undef x
#undef y
int construct_roads(vector<int> x, vector<int> y) {
    // edge case
    if (x.size() == 1) {
        build({}, {}, {}, {});
        return 1;
    }
    // sample solution
    /*vector<int> u, v, a, b;
    u.push_back(0);
    v.push_back(1);
    a.push_back(x[0]+1);
    b.push_back(y[0]-1);
    build(u, v, a, b);*/
    n = x.size();
    if(!check_possibility(n, x, y)) {
        return 0;
    }
    X = x;
    Y = y;
    points.assign(n, fountain());
    for(int i = 0; i < n; i++) {
        points[i] = fountain(x[i], y[i], i);
        fountain_at[x[i]][y[i]] = i + 1;
    }
    solve();
    // build solution
    build(ans_u, ans_v, ans_a, ans_b);
    return 1;
}

/*
5
4 4
4 6
6 4
4 2
2 4
*/

Compilation message

parks.cpp: In function 'std::pair<int, int> get_bench_when_in_intersection(int, int)':
parks.cpp:138:1: warning: control reaches end of non-void function [-Wreturn-type]
  138 | }
      | ^

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 268 ms 40852 KB Output is correct
10 Correct 18 ms 3920 KB Output is correct
11 Correct 109 ms 21200 KB Output is correct
12 Correct 28 ms 6124 KB Output is correct
13 Correct 19 ms 7140 KB Output is correct
14 Correct 1 ms 304 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 259 ms 40860 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 268 ms 40852 KB Output is correct
10 Correct 18 ms 3920 KB Output is correct
11 Correct 109 ms 21200 KB Output is correct
12 Correct 28 ms 6124 KB Output is correct
13 Correct 19 ms 7140 KB Output is correct
14 Correct 1 ms 304 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 259 ms 40860 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 1 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 0 ms 212 KB Output is correct
21 Correct 0 ms 212 KB Output is correct
22 Correct 0 ms 212 KB Output is correct
23 Correct 593 ms 72668 KB Output is correct
24 Correct 1 ms 212 KB Output is correct
25 Correct 3 ms 724 KB Output is correct
26 Correct 2 ms 596 KB Output is correct
27 Correct 1 ms 596 KB Output is correct
28 Correct 192 ms 26468 KB Output is correct
29 Correct 436 ms 48184 KB Output is correct
30 Correct 509 ms 61736 KB Output is correct
31 Correct 601 ms 72692 KB Output is correct
32 Correct 1 ms 212 KB Output is correct
33 Correct 1 ms 212 KB Output is correct
34 Correct 1 ms 212 KB Output is correct
35 Correct 1 ms 212 KB Output is correct
36 Correct 0 ms 212 KB Output is correct
37 Correct 0 ms 212 KB Output is correct
38 Correct 0 ms 212 KB Output is correct
39 Correct 0 ms 212 KB Output is correct
40 Correct 0 ms 212 KB Output is correct
41 Correct 0 ms 212 KB Output is correct
42 Correct 0 ms 212 KB Output is correct
43 Correct 1 ms 468 KB Output is correct
44 Correct 1 ms 468 KB Output is correct
45 Correct 403 ms 36436 KB Output is correct
46 Correct 616 ms 53076 KB Output is correct
47 Correct 617 ms 53328 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 268 ms 40852 KB Output is correct
10 Correct 18 ms 3920 KB Output is correct
11 Correct 109 ms 21200 KB Output is correct
12 Correct 28 ms 6124 KB Output is correct
13 Correct 19 ms 7140 KB Output is correct
14 Correct 1 ms 304 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 259 ms 40860 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 1 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 0 ms 212 KB Output is correct
21 Correct 0 ms 212 KB Output is correct
22 Correct 0 ms 212 KB Output is correct
23 Correct 593 ms 72668 KB Output is correct
24 Correct 1 ms 212 KB Output is correct
25 Correct 3 ms 724 KB Output is correct
26 Correct 2 ms 596 KB Output is correct
27 Correct 1 ms 596 KB Output is correct
28 Correct 192 ms 26468 KB Output is correct
29 Correct 436 ms 48184 KB Output is correct
30 Correct 509 ms 61736 KB Output is correct
31 Correct 601 ms 72692 KB Output is correct
32 Correct 1 ms 212 KB Output is correct
33 Correct 1 ms 212 KB Output is correct
34 Correct 1 ms 212 KB Output is correct
35 Correct 1 ms 212 KB Output is correct
36 Correct 0 ms 212 KB Output is correct
37 Correct 0 ms 212 KB Output is correct
38 Correct 0 ms 212 KB Output is correct
39 Correct 0 ms 212 KB Output is correct
40 Correct 0 ms 212 KB Output is correct
41 Correct 0 ms 212 KB Output is correct
42 Correct 0 ms 212 KB Output is correct
43 Correct 1 ms 468 KB Output is correct
44 Correct 1 ms 468 KB Output is correct
45 Correct 403 ms 36436 KB Output is correct
46 Correct 616 ms 53076 KB Output is correct
47 Correct 617 ms 53328 KB Output is correct
48 Correct 1 ms 212 KB Output is correct
49 Correct 0 ms 212 KB Output is correct
50 Correct 0 ms 212 KB Output is correct
51 Incorrect 0 ms 212 KB Tree @(5, 5) appears more than once: for edges on positions 1 and 4
52 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 268 ms 40852 KB Output is correct
10 Correct 18 ms 3920 KB Output is correct
11 Correct 109 ms 21200 KB Output is correct
12 Correct 28 ms 6124 KB Output is correct
13 Correct 19 ms 7140 KB Output is correct
14 Correct 1 ms 304 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 259 ms 40860 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 1275 ms 219744 KB Output is correct
21 Correct 1012 ms 128976 KB Output is correct
22 Correct 1195 ms 138328 KB Output is correct
23 Correct 810 ms 108240 KB Output is correct
24 Correct 82 ms 13004 KB Output is correct
25 Correct 73 ms 13120 KB Output is correct
26 Correct 78 ms 13080 KB Output is correct
27 Correct 867 ms 68012 KB Output is correct
28 Incorrect 885 ms 68088 KB Tree @(863, 999) appears more than once: for edges on positions 500 and 503
29 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 268 ms 40852 KB Output is correct
10 Correct 18 ms 3920 KB Output is correct
11 Correct 109 ms 21200 KB Output is correct
12 Correct 28 ms 6124 KB Output is correct
13 Correct 19 ms 7140 KB Output is correct
14 Correct 1 ms 304 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 259 ms 40860 KB Output is correct
17 Correct 957 ms 123644 KB Output is correct
18 Correct 999 ms 123640 KB Output is correct
19 Correct 1151 ms 161480 KB Output is correct
20 Correct 675 ms 53696 KB Output is correct
21 Correct 855 ms 64280 KB Output is correct
22 Correct 0 ms 212 KB Output is correct
23 Incorrect 104 ms 11936 KB Tree @(186073, 21295) appears more than once: for edges on positions 46 and 60
24 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 268 ms 40852 KB Output is correct
10 Correct 18 ms 3920 KB Output is correct
11 Correct 109 ms 21200 KB Output is correct
12 Correct 28 ms 6124 KB Output is correct
13 Correct 19 ms 7140 KB Output is correct
14 Correct 1 ms 304 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 259 ms 40860 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 1 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 0 ms 212 KB Output is correct
21 Correct 0 ms 212 KB Output is correct
22 Correct 0 ms 212 KB Output is correct
23 Correct 593 ms 72668 KB Output is correct
24 Correct 1 ms 212 KB Output is correct
25 Correct 3 ms 724 KB Output is correct
26 Correct 2 ms 596 KB Output is correct
27 Correct 1 ms 596 KB Output is correct
28 Correct 192 ms 26468 KB Output is correct
29 Correct 436 ms 48184 KB Output is correct
30 Correct 509 ms 61736 KB Output is correct
31 Correct 601 ms 72692 KB Output is correct
32 Correct 1 ms 212 KB Output is correct
33 Correct 1 ms 212 KB Output is correct
34 Correct 1 ms 212 KB Output is correct
35 Correct 1 ms 212 KB Output is correct
36 Correct 0 ms 212 KB Output is correct
37 Correct 0 ms 212 KB Output is correct
38 Correct 0 ms 212 KB Output is correct
39 Correct 0 ms 212 KB Output is correct
40 Correct 0 ms 212 KB Output is correct
41 Correct 0 ms 212 KB Output is correct
42 Correct 0 ms 212 KB Output is correct
43 Correct 1 ms 468 KB Output is correct
44 Correct 1 ms 468 KB Output is correct
45 Correct 403 ms 36436 KB Output is correct
46 Correct 616 ms 53076 KB Output is correct
47 Correct 617 ms 53328 KB Output is correct
48 Correct 1 ms 212 KB Output is correct
49 Correct 0 ms 212 KB Output is correct
50 Correct 0 ms 212 KB Output is correct
51 Incorrect 0 ms 212 KB Tree @(5, 5) appears more than once: for edges on positions 1 and 4
52 Halted 0 ms 0 KB -