oj.uz

Submission #143586

# Submission time Handle Problem Language Result Execution time Memory
143586 2019-08-14T16:50:25 Z VladaMG98 Split the Attractions (IOI19_split) C++17
18 / 100
 131 ms 19940 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.second);
        }
        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);
                }
            }
        }
    }
    assert(false);
}

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 8 ms 7416 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 7416 KB ok, correct split
6 Correct 8 ms 7416 KB ok, correct split
7 Correct 107 ms 19804 KB ok, correct split
8 Correct 98 ms 17640 KB ok, correct split
9 Correct 103 ms 17636 KB ok, correct split
10 Correct 96 ms 19008 KB ok, correct split
11 Correct 114 ms 19004 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 7416 KB ok, correct split
3 Correct 8 ms 7416 KB ok, correct split
4 Correct 113 ms 15316 KB ok, correct split
5 Correct 107 ms 15068 KB ok, correct split
6 Correct 101 ms 19056 KB ok, correct split
7 Correct 96 ms 17916 KB ok, correct split
8 Correct 131 ms 16380 KB ok, correct split
9 Correct 102 ms 15176 KB ok, correct split
10 Correct 75 ms 15696 KB ok, correct split
11 Correct 74 ms 15712 KB ok, correct split
12 Correct 77 ms 15740 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 93 ms 15300 KB ok, correct split
3 Correct 38 ms 10292 KB ok, correct split
4 Correct 8 ms 7416 KB ok, correct split
5 Correct 109 ms 16684 KB ok, correct split
6 Correct 109 ms 16576 KB ok, correct split
7 Correct 102 ms 16544 KB ok, correct split
8 Correct 108 ms 17244 KB ok, correct split
9 Correct 110 ms 16348 KB ok, correct split
10 Runtime error 51 ms 19940 KB Execution killed with signal 11 (could be triggered by violating memory limits)
11 Halted 0 ms 0 KB -

Subtask #4
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 7416 KB ok, correct split
2 Incorrect 10 ms 7416 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 8 ms 7416 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 7416 KB ok, correct split
6 Correct 8 ms 7416 KB ok, correct split
7 Correct 107 ms 19804 KB ok, correct split
8 Correct 98 ms 17640 KB ok, correct split
9 Correct 103 ms 17636 KB ok, correct split
10 Correct 96 ms 19008 KB ok, correct split
11 Correct 114 ms 19004 KB ok, correct split
12 Correct 8 ms 7416 KB ok, correct split
13 Correct 8 ms 7416 KB ok, correct split
14 Correct 8 ms 7416 KB ok, correct split
15 Correct 113 ms 15316 KB ok, correct split
16 Correct 107 ms 15068 KB ok, correct split
17 Correct 101 ms 19056 KB ok, correct split
18 Correct 96 ms 17916 KB ok, correct split
19 Correct 131 ms 16380 KB ok, correct split
20 Correct 102 ms 15176 KB ok, correct split
21 Correct 75 ms 15696 KB ok, correct split
22 Correct 74 ms 15712 KB ok, correct split
23 Correct 77 ms 15740 KB ok, correct split
24 Correct 8 ms 7416 KB ok, correct split
25 Correct 93 ms 15300 KB ok, correct split
26 Correct 38 ms 10292 KB ok, correct split
27 Correct 8 ms 7416 KB ok, correct split
28 Correct 109 ms 16684 KB ok, correct split
29 Correct 109 ms 16576 KB ok, correct split
30 Correct 102 ms 16544 KB ok, correct split
31 Correct 108 ms 17244 KB ok, correct split
32 Correct 110 ms 16348 KB ok, correct split
33 Runtime error 51 ms 19940 KB Execution killed with signal 11 (could be triggered by violating memory limits)
34 Halted 0 ms 0 KB -