Submission #143464

# Submission time Handle Problem Language Result Execution time Memory
143464 2019-08-14T07:01:26 Z icypiggy Split the Attractions (IOI19_split) C++14
22 / 100
166 ms 23624 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] = visit[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]);
        }
    }
	assert(low[x]==visit[x]);
}
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) {
              return ans;
                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);
                        }
                    }
                }
                //assert(ctr==b);
                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++;
                        }
                    }
                }
                //assert(ctr==a);
                for(int k=0; k<n; k++) {
                    //assert(ans[k]!=0);
                }
                return ans;
            }
        }
    }
    assert(false);
    return p;
}
# Verdict Execution time Memory Grader output
1 Correct 11 ms 10488 KB ok, correct split
2 Runtime error 24 ms 21112 KB Execution killed with signal 11 (could be triggered by violating memory limits)
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 13 ms 10488 KB ok, correct split
2 Runtime error 25 ms 21116 KB Execution killed with signal 11 (could be triggered by violating memory limits)
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 11 ms 10616 KB ok, correct split
2 Correct 109 ms 18604 KB ok, correct split
3 Correct 45 ms 13732 KB ok, correct split
4 Correct 11 ms 10616 KB ok, correct split
5 Correct 114 ms 22648 KB ok, correct split
6 Correct 166 ms 22264 KB ok, correct split
7 Correct 121 ms 22140 KB ok, correct split
8 Correct 131 ms 23624 KB ok, correct split
9 Correct 126 ms 22008 KB ok, correct split
10 Correct 38 ms 13176 KB ok, no valid answer
11 Correct 62 ms 14556 KB ok, no valid answer
12 Correct 113 ms 18036 KB ok, no valid answer
13 Correct 111 ms 18472 KB ok, no valid answer
14 Correct 73 ms 17776 KB ok, no valid answer
# Verdict Execution time Memory Grader output
1 Runtime error 24 ms 21112 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 11 ms 10488 KB ok, correct split
2 Runtime error 24 ms 21112 KB Execution killed with signal 11 (could be triggered by violating memory limits)
3 Halted 0 ms 0 KB -