oj.uz

Submission #143967

# Submission time Handle Problem Language Result Execution time Memory
143967 2019-08-15T13:52:07 Z VladaMG98 Split the Attractions (IOI19_split) C++17
18 / 100
 160 ms 19720 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);
                }
            }
        }
    }
  	assert(false);
    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 8 ms 7416 KB ok, correct split
3 Correct 8 ms 7416 KB ok, correct split
4 Correct 9 ms 7416 KB ok, correct split
5 Correct 9 ms 7416 KB ok, correct split
6 Correct 6 ms 7416 KB ok, correct split
7 Correct 115 ms 19720 KB ok, correct split
8 Correct 108 ms 17528 KB ok, correct split
9 Correct 114 ms 17756 KB ok, correct split
10 Correct 104 ms 18908 KB ok, correct split
11 Correct 110 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 9 ms 7464 KB ok, correct split
3 Correct 8 ms 7416 KB ok, correct split
4 Correct 115 ms 15360 KB ok, correct split
5 Correct 96 ms 15068 KB ok, correct split
6 Correct 105 ms 19040 KB ok, correct split
7 Correct 115 ms 17900 KB ok, correct split
8 Correct 132 ms 16404 KB ok, correct split
9 Correct 108 ms 15040 KB ok, correct split
10 Correct 74 ms 15708 KB ok, correct split
11 Correct 77 ms 15648 KB ok, correct split
12 Correct 79 ms 15680 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 15324 KB ok, correct split
3 Correct 39 ms 10292 KB ok, correct split
4 Correct 8 ms 7416 KB ok, correct split
5 Correct 138 ms 16812 KB ok, correct split
6 Correct 122 ms 16732 KB ok, correct split
7 Correct 115 ms 16476 KB ok, correct split
8 Correct 117 ms 17344 KB ok, correct split
9 Correct 160 ms 16456 KB ok, correct split
10 Incorrect 39 ms 10092 KB secret mismatch
11 Halted 0 ms 0 KB -

Subtask #4
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB ok, correct split
2 Incorrect 7 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 9 ms 7416 KB ok, correct split
5 Correct 9 ms 7416 KB ok, correct split
6 Correct 6 ms 7416 KB ok, correct split
7 Correct 115 ms 19720 KB ok, correct split
8 Correct 108 ms 17528 KB ok, correct split
9 Correct 114 ms 17756 KB ok, correct split
10 Correct 104 ms 18908 KB ok, correct split
11 Correct 110 ms 18908 KB ok, correct split
12 Correct 8 ms 7416 KB ok, correct split
13 Correct 9 ms 7464 KB ok, correct split
14 Correct 8 ms 7416 KB ok, correct split
15 Correct 115 ms 15360 KB ok, correct split
16 Correct 96 ms 15068 KB ok, correct split
17 Correct 105 ms 19040 KB ok, correct split
18 Correct 115 ms 17900 KB ok, correct split
19 Correct 132 ms 16404 KB ok, correct split
20 Correct 108 ms 15040 KB ok, correct split
21 Correct 74 ms 15708 KB ok, correct split
22 Correct 77 ms 15648 KB ok, correct split
23 Correct 79 ms 15680 KB ok, correct split
24 Correct 8 ms 7416 KB ok, correct split
25 Correct 101 ms 15324 KB ok, correct split
26 Correct 39 ms 10292 KB ok, correct split
27 Correct 8 ms 7416 KB ok, correct split
28 Correct 138 ms 16812 KB ok, correct split
29 Correct 122 ms 16732 KB ok, correct split
30 Correct 115 ms 16476 KB ok, correct split
31 Correct 117 ms 17344 KB ok, correct split
32 Correct 160 ms 16456 KB ok, correct split
33 Incorrect 39 ms 10092 KB secret mismatch
34 Halted 0 ms 0 KB -