oj.uz

Submission #143966

# Submission time Handle Problem Language Result Execution time Memory
143966 2019-08-15T13:50:43 Z VladaMG98 Split the Attractions (IOI19_split) C++17
18 / 100
 150 ms 19696 KB 
#include <bits/stdc++.h>
#include "split.h"
using namespace std;
 
const int MAXN = 100010;
int subtree_size[MAXN];
vector<int> adj[MAXN];
int parent[MAXN];
 
void dfs(int src = 0, int prev = -1) {
    //printf("dfs %d %d\n", src, prev);
    subtree_size[src] = 1;
    parent[src] = prev;
    for(auto &xt : adj[src]) {
        if(xt - prev) {
            dfs(xt, src);
            subtree_size[src] += subtree_size[xt];
        }
    }
}
 
vector<int> get_solution(vector<int> v1, int n1, vector<int> v2, int n2, int n) {
    vector<int> ans(n, 6 - n1 - n2);
    for(auto &x : v1) {
        ans[x] = n1;
    }
    for(auto &x : v2) {
        ans[x] = n2;
    }
    return ans;
}
 
bool marked[MAXN];
vector<int> extract(int src, int wrong, int sz) {
    marked[wrong] = true;
    vector<int> ans;
    stack<int> nodes;
    nodes.push(src);
    marked[src] = true;
    while((int)ans.size() < sz) {
        int node = nodes.top();
        nodes.pop();
        ans.push_back(node);
        for(auto &x : adj[node]) {
            if(!marked[x]) {
                marked[x] = true;
                nodes.push(x);
            }
        }
    }
    for(auto &x : ans) {
        marked[x] = false;
    }
    marked[wrong] = false;
    return ans;
}
 
vector<int> blank(int n) {
    vector<int> ans(n, 0);
    return ans;
}
 
int dsu[MAXN];
 
void init_set(int x) {
    dsu[x] = x;
}
 
int get(int x) {
    if(dsu[x] == x) return x;
    return dsu[x] = get(dsu[x]);
}
 
bool unite(int x, int y) {
    int xr = get(x), yr = get(y);
    if(xr == yr) return false;
    if(rand() % 2) swap(xr, yr);
    dsu[xr] = yr;
    return true;
}
 
void create_spanning_tree(int n, vector<int> &st_p, vector<int> &st_q, vector<int> p, vector<int> q) {
    for(int i = 0; i < n; i++) {
        init_set(i);
    }
    int m = (int)p.size();
    for(int i = 0; i < m; i++) {
        if(unite(p[i], q[i])) {
            st_p.push_back(p[i]);
            st_q.push_back(q[i]);
        }
    }
    //assert((int)st_p.size() == n - 1);
}
 
int belongs[MAXN];
set<int> comp_adj[MAXN];
int cnt_nodes[MAXN];
 
int comp_size;
vector<int> comp_comp;
bool comp_mark[MAXN];
void dfs2(int src) {
    comp_size += cnt_nodes[src];
    comp_mark[src] = true;
    comp_comp.push_back(src);
    for(auto &xt : comp_adj[src]) {
        if(!comp_mark[xt]) {
            dfs2(xt);
        }
    }
}
 
vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q) {
    pair<int, int> arr[] = {{a, 1}, {b, 2}, {c, 3}};
    sort(arr, arr + 3);
    int A = arr[0].first, B = arr[1].first, C = arr[2].first;
    vector<int> st_p, st_q;
    create_spanning_tree(n, st_p, st_q, p, q);
    int m = (int)p.size();
    for(int i = 0; i < n - 1; i++) {
        adj[st_p[i]].push_back(st_q[i]);
        adj[st_q[i]].push_back(st_p[i]);
    }
    dfs();
    //for(int i = 0; i < n; i++) {
    //   printf("subtree_size[%d] = %d\n", i, subtree_size[i]);
    //}
    for(int i = 0; i < m; i++) {
        int u = p[i], v = q[i];
        if(subtree_size[u] > subtree_size[v]) swap(u, v);
        int under = subtree_size[u];
        int rest = n - under;
        if(under >= A && rest >= A) {
            //printf("found for edge %d - %d\n", u, v);
            //we've got a solution
            vector<int> set_A, set_B;
            if(under < rest) {
                set_A = extract(u, v, A);
                set_B = extract(v, u, B);
            } else {
                set_A = extract(v, u, A);
                set_B = extract(u, v, B);
            }
            return get_solution(set_A, arr[0].second, set_B, arr[1].second, n);
        }
    }
    //there is no edge connecting two subtrees of sizes >= a
    //meaning that it's a star with all subtrees attached of size < a
    //in tree, there is no such solution
    for(int node = 0; node < n; node++) {
        vector<pair<int, int>> sizes;
        int sm = 0;
        for(auto &xt : adj[node]) {
            if(xt != parent[node]) {
                sizes.push_back({subtree_size[xt], xt});
                sm += subtree_size[xt];
            }
        }
        if(node) {
            sizes.push_back({n - 1 - sm, parent[node]});
        }
        int mx = 0;
        for(auto &pr : sizes) {
            mx = max(mx, pr.first);
        }
        if(mx < A) {
            printf("I am deciding on node %d\n", node);
            for(int i = 0; i < (int)sizes.size(); i++) {
                vector<int> comp_here = extract(sizes[i].second, node, sizes[i].first);
                for(auto &x : comp_here) {
                    belongs[x] = i + 1;
                    marked[x] = false;
                }
                marked[node] = false;
                cnt_nodes[i + 1] = sizes[i].first;
            }
            int new_nodes = (int)sizes.size();
            for(int i = 0; i < m; i++) {
                if(p[i] != node && q[i] != node) {
                    comp_adj[belongs[p[i]]].insert(belongs[q[i]]);
                    comp_adj[belongs[q[i]]].insert(belongs[p[i]]);
                }
            }
            for(int i = 1; i <= new_nodes; i++) {
                if(marked[i]) continue;
                comp_size = 0;
                comp_comp.clear();
                dfs2(i);
                for(auto &x : comp_comp) {
                    comp_mark[x] = false;
                }
                if(comp_size >= A) {
                    //we have a solution
                    int start_node = sizes[i - 1].second;
                    vector<int> ans_A = extract(start_node, node, A);
                    for(auto &x : ans_A) {
                        marked[x] = true;
                    }
                    vector<int> ans_B = extract(node, MAXN - 1, B);
                    return get_solution(ans_A, arr[0].second, ans_B, arr[1].second, n);
                } else {
                    return blank(n);
                }
            }
        }
    }
    return blank(n);
}

Compilation message

split.cpp: In function 'std::vector<int> find_split(int, int, int, int, std::vector<int>, std::vector<int>)':
split.cpp:117:45: warning: unused variable 'C' [-Wunused-variable]
     int A = arr[0].first, B = arr[1].first, C = arr[2].first;
                                             ^

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB ok, correct split
2 Correct 9 ms 7388 KB ok, correct split
3 Correct 8 ms 7416 KB ok, correct split
4 Correct 8 ms 7416 KB ok, correct split
5 Correct 8 ms 7468 KB ok, correct split
6 Correct 8 ms 7416 KB ok, correct split
7 Correct 124 ms 19696 KB ok, correct split
8 Correct 109 ms 17500 KB ok, correct split
9 Correct 150 ms 17628 KB ok, correct split
10 Correct 108 ms 18908 KB ok, correct split
11 Correct 122 ms 18908 KB ok, correct split

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB ok, correct split
2 Correct 8 ms 7336 KB ok, correct split
3 Correct 8 ms 7416 KB ok, correct split
4 Correct 116 ms 15340 KB ok, correct split
5 Correct 95 ms 15068 KB ok, correct split
6 Correct 112 ms 18908 KB ok, correct split
7 Correct 123 ms 17940 KB ok, correct split
8 Correct 136 ms 16404 KB ok, correct split
9 Correct 112 ms 14940 KB ok, correct split
10 Correct 75 ms 15668 KB ok, correct split
11 Correct 74 ms 15612 KB ok, correct split
12 Correct 78 ms 15708 KB ok, correct split

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB ok, correct split
2 Correct 101 ms 15232 KB ok, correct split
3 Correct 38 ms 10264 KB ok, correct split
4 Correct 8 ms 7420 KB ok, correct split
5 Correct 102 ms 16700 KB ok, correct split
6 Correct 108 ms 16632 KB ok, correct split
7 Correct 107 ms 16492 KB ok, correct split
8 Correct 102 ms 17244 KB ok, correct split
9 Correct 110 ms 16320 KB ok, correct split
10 Incorrect 38 ms 10068 KB secret mismatch
11 Halted 0 ms 0 KB -

Subtask #4
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 7416 KB ok, correct split
2 Incorrect 8 ms 7388 KB secret mismatch
3 Halted 0 ms 0 KB -

Subtask #5
0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB ok, correct split
2 Correct 9 ms 7388 KB ok, correct split
3 Correct 8 ms 7416 KB ok, correct split
4 Correct 8 ms 7416 KB ok, correct split
5 Correct 8 ms 7468 KB ok, correct split
6 Correct 8 ms 7416 KB ok, correct split
7 Correct 124 ms 19696 KB ok, correct split
8 Correct 109 ms 17500 KB ok, correct split
9 Correct 150 ms 17628 KB ok, correct split
10 Correct 108 ms 18908 KB ok, correct split
11 Correct 122 ms 18908 KB ok, correct split
12 Correct 8 ms 7416 KB ok, correct split
13 Correct 8 ms 7336 KB ok, correct split
14 Correct 8 ms 7416 KB ok, correct split
15 Correct 116 ms 15340 KB ok, correct split
16 Correct 95 ms 15068 KB ok, correct split
17 Correct 112 ms 18908 KB ok, correct split
18 Correct 123 ms 17940 KB ok, correct split
19 Correct 136 ms 16404 KB ok, correct split
20 Correct 112 ms 14940 KB ok, correct split
21 Correct 75 ms 15668 KB ok, correct split
22 Correct 74 ms 15612 KB ok, correct split
23 Correct 78 ms 15708 KB ok, correct split
24 Correct 8 ms 7416 KB ok, correct split
25 Correct 101 ms 15232 KB ok, correct split
26 Correct 38 ms 10264 KB ok, correct split
27 Correct 8 ms 7420 KB ok, correct split
28 Correct 102 ms 16700 KB ok, correct split
29 Correct 108 ms 16632 KB ok, correct split
30 Correct 107 ms 16492 KB ok, correct split
31 Correct 102 ms 17244 KB ok, correct split
32 Correct 110 ms 16320 KB ok, correct split
33 Incorrect 38 ms 10068 KB secret mismatch
34 Halted 0 ms 0 KB -