Submission #785714

#	Time	Username	Problem	Language	Result	Execution time	Memory
785714		1bin	Split the Attractions (IOI19_split)	C++14	100 / 100	96 ms	31384 KiB

split

#include <bits/stdc++.h>
//#include "split.h"

using namespace std;

#define all(v) v.begin(), v.end()
typedef long long ll;
const int NMAX = 1e5 + 5;
int ans, n, A, B, label[NMAX], cnt;
int dfsn[NMAX], low[NMAX], sz[NMAX], t;
vector<int> adj[NMAX];

void color(int x, int c, int all = 0){
    if(label[x] != -1) return;
    label[x] = (cnt-- > 0 ? c : 2);
    for(int& nx : adj[x])
        if(all || dfsn[nx] > dfsn[x]) color(nx, c, all);
    return;
}

void dfs(int x, int p){
    vector<int> C;
    dfsn[x] = low[x] = ++t;
    sz[x] = 1;
    int mx = 0;
    for(int& nx : adj[x])
        if(nx != p) {
            if(!dfsn[nx]){
                dfs(nx, x);
                low[x] = min(low[x], low[nx]);
                sz[x] += sz[nx];
                C.emplace_back(nx); 
                mx = max(mx, sz[nx]);
            }
            else low[x] = min(low[x], dfsn[nx]);
        }

    if(!ans && sz[x] >= A && mx < A){
        int d = sz[x], u = n - d;
        vector<int> v;
        for(int& nx : C){
            if(d - sz[nx] >= A && low[nx] < dfsn[x]) u += sz[nx], d -= sz[nx];
            else v.emplace_back(nx);
        }
        if(u >= A){
            ans = 1;
            if(u >= B) {
                cnt = A - 1; label[x] = 0;
                for(int& y : v) color(y, 0);
                cnt = B; color(p, 1, 1);
            }
            else{
                cnt = B - 1; label[x] = 1;
                for(int& y : v) color(y, 1);
                cnt = A; color(p, 0, 1);
            }
        }
        else ans = -1;
    }
    return;
}

vector<int> find_split(int n_, int a, int b, int c, vector<int> p, vector<int> q) {
    n = n_;
    vector<pair<int, int>> arr = {{a, 1}, {b, 2}, {c, 3}};
    sort(all(arr));
    A = arr[0].first;
    B = arr[1].first;
	vector<int> res(n, 0);
    for(int i = 0; i < p.size(); i++){
        adj[p[i]].emplace_back(q[i]);
        adj[q[i]].emplace_back(p[i]);
    }
    memset(label, -1, sizeof(label));
    dfs(0, -1);
    if(ans == -1) return res;
    for(int i = 0; i < n; i++) res[i] = arr[label[i]].second;
	return res;
}

/*
int main(void){
    int n, m, a, b, c;
    cin >> n >> a >> b >> c;
    cin >> m;
    vector<int> p(m), q(m);
    for(int i = 0; i < m; i++) cin >> p[i] >> q[i];
    auto v = find_split(n, a, b, c, p, q);
    for(int& x : v) cout << x << ' ';
    return 0;
}
*/

Compilation message (stderr)

split.cpp: In function 'std::vector<int> find_split(int, int, int, int, std::vector<int>, std::vector<int>)':
split.cpp:70:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |     for(int i = 0; i < p.size(); i++){
      |                    ~~^~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 24 / 24
• Subtask 5: 36 / 36