oj.uz

Submission #143588

# Submission time Handle Problem Language Result Execution time Memory
143588 2019-08-14T16:51:53 Z VladaMG98 Split the Attractions (IOI19_split) C++17
18 / 100
 155 ms 19912 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 7324 KB ok, correct split
4 Correct 8 ms 7416 KB ok, correct split
5 Correct 8 ms 7316 KB ok, correct split
6 Correct 8 ms 7416 KB ok, correct split
7 Correct 110 ms 19648 KB ok, correct split
8 Correct 97 ms 17500 KB ok, correct split
9 Correct 104 ms 17628 KB ok, correct split
10 Correct 101 ms 19036 KB ok, correct split
11 Correct 115 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 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 92 ms 15196 KB ok, correct split
6 Correct 108 ms 19008 KB ok, correct split
7 Correct 102 ms 18012 KB ok, correct split
8 Correct 136 ms 16404 KB ok, correct split
9 Correct 94 ms 15068 KB ok, correct split
10 Correct 73 ms 15708 KB ok, correct split
11 Correct 75 ms 15708 KB ok, correct split
12 Correct 80 ms 15688 KB ok, correct split

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7444 KB ok, correct split
2 Correct 97 ms 15324 KB ok, correct split
3 Correct 38 ms 10292 KB ok, correct split
4 Correct 8 ms 7416 KB ok, correct split
5 Correct 107 ms 16732 KB ok, correct split
6 Correct 124 ms 16604 KB ok, correct split
7 Correct 119 ms 16476 KB ok, correct split
8 Correct 104 ms 17372 KB ok, correct split
9 Correct 155 ms 16348 KB ok, correct split
10 Runtime error 44 ms 19912 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 9 ms 7416 KB ok, correct split
2 Runtime error 19 ms 14744 KB Execution killed with signal 11 (could be triggered by violating memory limits)
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 7324 KB ok, correct split
4 Correct 8 ms 7416 KB ok, correct split
5 Correct 8 ms 7316 KB ok, correct split
6 Correct 8 ms 7416 KB ok, correct split
7 Correct 110 ms 19648 KB ok, correct split
8 Correct 97 ms 17500 KB ok, correct split
9 Correct 104 ms 17628 KB ok, correct split
10 Correct 101 ms 19036 KB ok, correct split
11 Correct 115 ms 18908 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 92 ms 15196 KB ok, correct split
17 Correct 108 ms 19008 KB ok, correct split
18 Correct 102 ms 18012 KB ok, correct split
19 Correct 136 ms 16404 KB ok, correct split
20 Correct 94 ms 15068 KB ok, correct split
21 Correct 73 ms 15708 KB ok, correct split
22 Correct 75 ms 15708 KB ok, correct split
23 Correct 80 ms 15688 KB ok, correct split
24 Correct 8 ms 7444 KB ok, correct split
25 Correct 97 ms 15324 KB ok, correct split
26 Correct 38 ms 10292 KB ok, correct split
27 Correct 8 ms 7416 KB ok, correct split
28 Correct 107 ms 16732 KB ok, correct split
29 Correct 124 ms 16604 KB ok, correct split
30 Correct 119 ms 16476 KB ok, correct split
31 Correct 104 ms 17372 KB ok, correct split
32 Correct 155 ms 16348 KB ok, correct split
33 Runtime error 44 ms 19912 KB Execution killed with signal 11 (could be triggered by violating memory limits)
34 Halted 0 ms 0 KB -