oj.uz

Submission #143452

# Submission time Handle Problem Language Result Execution time Memory
143452 2019-08-14T06:17:19 Z icypiggy Split the Attractions (IOI19_split) C++14
18 / 100
 187 ms 27896 KB 
#include <bits/stdc++.h>
using namespace std;
const int n_max = 2e5+1e3;
int visit[n_max];
int low[n_max];
int subtree[n_max];
vector<int> adj[n_max];
vector<int> child[n_max];
int parent[n_max];
int time_global = 0;
void dfs(int x) {
    subtree[x] = 1;
    visit[x] = time_global;
    time_global++;
    low[x] = x;
    for(int i: adj[x]) {
        if(visit[i]==-1) {
            parent[i] = x;
            child[x].push_back(i);
            dfs(i);
            subtree[x] += subtree[i];
            low[x] = min(low[x], low[i]);
        } else if (i != parent[x]) {
            low[x] = min(low[x], visit[i]);
        }
    }
}
vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q) {
    // assume a<=b<=c
    vector<pair<int,int>> vp = {make_pair(a,1),make_pair(b,2),make_pair(c,3)};
    sort(vp.begin(), vp.end());
    int small = vp[0].second;
    int mid = vp[1].second;
    int big = vp[2].second;
    a = vp[0].first;
    b = vp[1].first;
    c = vp[2].first;

    memset(visit, -1, sizeof(visit));
    for(int i=0; i<(int) p.size(); i++) {
        adj[p[i]].push_back(q[i]);
        adj[q[i]].push_back(p[i]);
    }
    dfs(0);
    vector<int> ans(n,0);
    for(int i=0; i<n; i++) {
        // assume c>=a
        // check: a+c or b+c?
        if(subtree[i]>=a && subtree[i]<=b+c) {
            if(subtree[i]>a+c) {
                swap(a,b);
                swap(small,mid);
            }
            queue<int> bfs;
            bfs.push(i);
            int ctr = 0;
            while(!bfs.empty()) {
                int next = bfs.front();
                ans[next] = (ctr<a ? small : big);
                ctr++;
                bfs.pop();
                for(int k: child[next]) {
                    bfs.push(k);
                }
            }
            bfs.push(0);
            ctr = 0;
            while(!bfs.empty()) {
                int next = bfs.front();
                ans[next] = (ctr<b ? mid : big);
                ctr++;
                bfs.pop();
                for(int k: child[next]) {
                    if(ans[k]==0) {
                        bfs.push(k);
                    }
                }
            }
            for(int k=0; k<n; k++) {
                assert(ans[k]!=0);
            }
            return ans;
        } else if(subtree[i]>b+c) {
            // if have heavy node with all light children
            bool all_light = true;
            for(int j: child[i]) {
                if(subtree[j]>=a) {
                    all_light = false;
                    // break;
                }
            }
            if(all_light) {
                if(i==0) {
                    assert(child[i].size()>=3);
                    return ans;
                }
                int minsize = 1;
                vector<int> tmp; // consists of all the children to be taken
                for(int j: child[i]) {
                    // add all those with bad lowtime
                    if(low[j]>= visit[i]) {
                        minsize += subtree[j];
                        tmp.push_back(j);
                    }
                }
                if(minsize > b+c) {
                    return ans;
                }
                for(int j: child[i]) {
                    // add the relevant subtrees
                    if(low[j]<visit[i] && minsize < b) {
                        minsize += subtree[j];
                        tmp.push_back(j);
                    }
                }
                assert(minsize >= b);
                assert(minsize <= b+c);
                // now for each subtree, color its children completely except that some are colored with 3
                int ctr = 1;
                ans[i] = mid;
                queue<int> bfs;
                for(int j: tmp) {
                    bfs.push(j);
                    while(!bfs.empty()) {
                        int next = bfs.front();
                        assert(ans[next]==0);
                        ans[next] = (ctr<b ? mid : big);
                        ctr++;
                        bfs.pop();
                        for(int k: child[next]) {
                            bfs.push(k);
                        }
                    }
                }
                ctr = 1;
                bfs.push(0); // we know that 0 is not the root
                ans[0] = small;
                while(!bfs.empty()) {
                    int next = bfs.front();
                    bfs.pop();
                    for(int k: adj[next]) {
                        if(ans[k]==0) {
                            bfs.push(k);
                            ans[k] = (ctr<a ? small : big);
                            ctr++;
                        }
                    }
                }
                return ans;
            }
        }
    }
    assert(false);
    return p;
}
// note parent here means a different thing oops
int findset(int x) {
    return parent[x]==x ? x : parent[x] = findset(parent[x]);
}
void onion(int x, int y) {
    parent[findset(x)] = parent[findset(y)];
}

void verify_ans(int n, int a, int b, int c, vector<int> p, vector<int> q, vector<int> ans) {
    if(ans[0]!=0) {
        int good = 0;
        for(int i=0; i<n; i++) parent[i] = i;
        int onion_count[4] = {0,a-1,b-1,c-1};
        for(int i=0; i<(int) p.size(); i++) {
            if(ans[p[i]]==ans[q[i]] && findset(p[i])!=findset(q[i])) {
                onion(p[i], q[i]);
                onion_count[ans[p[i]]]--;
                if(onion_count[ans[p[i]]]==0) good++;
            }
        }
        int counter[4] = {0,a,b,c};
        for(int i:ans) {
            counter[i]--;
        }
        assert(counter[1]==0);
        assert(counter[2]==0);
        assert(counter[3]==0);
        assert(good>=2);
    } else {
        //assert(false);
    }
}
pair<vector<int>, vector<int>> gen_graph(int n) {
    bool adj[n][n];
    int components = n;
    vector<int> p;
    vector<int> q;
    for(int i=0; i<n; i++) parent[i] = i;
    while(true) {
        for(int i=0; i<n; i++) {
            for(int j=0; j<i; j++) {
                if((rand()%100==0) && adj[i][j]==false) {
                    if(findset(i)!=findset(j)) {
                        adj[i][j] = true;
                        onion(i,j);
                        p.push_back(i);
                        q.push_back(j);
                        components--;
                        if(components==1) {
                            for(int i=0; i<p.size(); i++) {
                                //cout << p[i] << " " << q[i] << "\n";
                            }
                            return make_pair(p,q);
                        }
                        // this generates random trees
                    }
                }
            }
        }
    }
}

Compilation message

split.cpp: In function 'std::pair<std::vector<int>, std::vector<int> > gen_graph(int)':
split.cpp:205:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                             for(int i=0; i<p.size(); i++) {
                                          ~^~~~~~~~~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 10616 KB ok, correct split
2 Correct 11 ms 10488 KB ok, correct split
3 Correct 11 ms 10488 KB ok, correct split
4 Correct 11 ms 10488 KB ok, correct split
5 Correct 11 ms 10616 KB ok, correct split
6 Correct 11 ms 10616 KB ok, correct split
7 Correct 134 ms 27448 KB ok, correct split
8 Correct 140 ms 25184 KB ok, correct split
9 Correct 126 ms 24412 KB ok, correct split
10 Correct 136 ms 27768 KB ok, correct split
11 Correct 131 ms 27896 KB ok, correct split

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 10488 KB ok, correct split
2 Correct 10 ms 10488 KB ok, correct split
3 Correct 11 ms 10488 KB ok, correct split
4 Correct 187 ms 23612 KB ok, correct split
5 Correct 110 ms 18552 KB ok, correct split
6 Correct 131 ms 27716 KB ok, correct split
7 Correct 163 ms 24944 KB ok, correct split
8 Correct 157 ms 21240 KB ok, correct split
9 Correct 112 ms 20088 KB ok, correct split
10 Correct 74 ms 18028 KB ok, correct split
11 Correct 74 ms 18052 KB ok, correct split
12 Correct 80 ms 18160 KB ok, correct split

Subtask #3
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 10488 KB ok, correct split
2 Correct 113 ms 18660 KB ok, correct split
3 Correct 44 ms 13816 KB ok, correct split
4 Correct 10 ms 10488 KB ok, correct split
5 Correct 126 ms 22620 KB ok, correct split
6 Correct 122 ms 22392 KB ok, correct split
7 Correct 128 ms 22156 KB ok, correct split
8 Correct 134 ms 23508 KB ok, correct split
9 Correct 124 ms 22048 KB ok, correct split
10 Correct 38 ms 13304 KB ok, no valid answer
11 Correct 54 ms 14588 KB ok, no valid answer
12 Correct 96 ms 18496 KB ok, no valid answer
13 Incorrect 109 ms 18680 KB answer contains both zero and positive values
14 Halted 0 ms 0 KB -

Subtask #4
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 10488 KB ok, correct split
2 Correct 11 ms 10616 KB ok, no valid answer
3 Correct 11 ms 10616 KB ok, correct split
4 Correct 11 ms 10616 KB ok, correct split
5 Correct 13 ms 10616 KB ok, correct split
6 Correct 11 ms 10616 KB ok, correct split
7 Correct 13 ms 10488 KB ok, correct split
8 Correct 11 ms 10616 KB ok, correct split
9 Correct 14 ms 10872 KB ok, correct split
10 Correct 13 ms 10872 KB ok, correct split
11 Correct 11 ms 10616 KB ok, correct split
12 Correct 13 ms 10872 KB ok, correct split
13 Correct 11 ms 10488 KB ok, correct split
14 Correct 11 ms 10492 KB ok, correct split
15 Correct 11 ms 10584 KB ok, correct split
16 Correct 11 ms 10616 KB ok, correct split
17 Correct 11 ms 10488 KB ok, correct split
18 Correct 11 ms 10616 KB ok, correct split
19 Correct 11 ms 10620 KB ok, correct split
20 Correct 12 ms 10744 KB ok, correct split
21 Correct 13 ms 10848 KB ok, correct split
22 Correct 13 ms 10792 KB ok, correct split
23 Correct 13 ms 10888 KB ok, correct split
24 Correct 13 ms 10872 KB ok, correct split
25 Correct 12 ms 10872 KB ok, correct split
26 Correct 13 ms 10872 KB ok, correct split
27 Correct 13 ms 10844 KB ok, correct split
28 Correct 13 ms 10744 KB ok, correct split
29 Correct 11 ms 10616 KB ok, correct split
30 Correct 13 ms 10744 KB ok, correct split
31 Correct 11 ms 10616 KB ok, correct split
32 Correct 11 ms 10616 KB ok, correct split
33 Correct 11 ms 10616 KB ok, correct split
34 Correct 13 ms 10744 KB ok, correct split
35 Correct 13 ms 10744 KB ok, correct split
36 Correct 13 ms 10744 KB ok, correct split
37 Correct 13 ms 10872 KB ok, correct split
38 Correct 13 ms 10872 KB ok, correct split
39 Correct 13 ms 10872 KB ok, correct split
40 Correct 13 ms 10872 KB ok, correct split
41 Correct 12 ms 10616 KB ok, correct split
42 Correct 12 ms 10616 KB ok, correct split
43 Correct 16 ms 10876 KB ok, correct split
44 Correct 14 ms 10872 KB ok, correct split
45 Correct 13 ms 10872 KB ok, correct split
46 Correct 13 ms 10872 KB ok, correct split
47 Incorrect 12 ms 10876 KB answer contains both zero and positive values
48 Halted 0 ms 0 KB -

Subtask #5
0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 10616 KB ok, correct split
2 Correct 11 ms 10488 KB ok, correct split
3 Correct 11 ms 10488 KB ok, correct split
4 Correct 11 ms 10488 KB ok, correct split
5 Correct 11 ms 10616 KB ok, correct split
6 Correct 11 ms 10616 KB ok, correct split
7 Correct 134 ms 27448 KB ok, correct split
8 Correct 140 ms 25184 KB ok, correct split
9 Correct 126 ms 24412 KB ok, correct split
10 Correct 136 ms 27768 KB ok, correct split
11 Correct 131 ms 27896 KB ok, correct split
12 Correct 11 ms 10488 KB ok, correct split
13 Correct 10 ms 10488 KB ok, correct split
14 Correct 11 ms 10488 KB ok, correct split
15 Correct 187 ms 23612 KB ok, correct split
16 Correct 110 ms 18552 KB ok, correct split
17 Correct 131 ms 27716 KB ok, correct split
18 Correct 163 ms 24944 KB ok, correct split
19 Correct 157 ms 21240 KB ok, correct split
20 Correct 112 ms 20088 KB ok, correct split
21 Correct 74 ms 18028 KB ok, correct split
22 Correct 74 ms 18052 KB ok, correct split
23 Correct 80 ms 18160 KB ok, correct split
24 Correct 11 ms 10488 KB ok, correct split
25 Correct 113 ms 18660 KB ok, correct split
26 Correct 44 ms 13816 KB ok, correct split
27 Correct 10 ms 10488 KB ok, correct split
28 Correct 126 ms 22620 KB ok, correct split
29 Correct 122 ms 22392 KB ok, correct split
30 Correct 128 ms 22156 KB ok, correct split
31 Correct 134 ms 23508 KB ok, correct split
32 Correct 124 ms 22048 KB ok, correct split
33 Correct 38 ms 13304 KB ok, no valid answer
34 Correct 54 ms 14588 KB ok, no valid answer
35 Correct 96 ms 18496 KB ok, no valid answer
36 Incorrect 109 ms 18680 KB answer contains both zero and positive values
37 Halted 0 ms 0 KB -