Submission #1042602

#	Time	Username	Problem	Language	Result	Execution time	Memory
1042602		idas	Split the Attractions (IOI19_split)	C++17	22 / 100	455 ms	1048576 KiB

split

#include "split.h"
#include <bits/stdc++.h>
#define FOR(i, begin, end) for(int i=(begin); i<(end); i++)
#define pb push_back

using namespace std;
typedef vector<int> vi;

const int MxN=1e5+10;
int n, m, dp[MxN], s[3];
vi ad[MxN];

void pre(int u, int pst=-1) {
    dp[u]=1;
    for(auto it : ad[u]) {
        if(it==pst) continue;
        pre(it, u);
        dp[u]+=dp[it];
    }
}

int x=-1, y=-1;
void dfs(int u, int pst=-1, int up=0) {
    if(up>=s[0] && dp[u]>=s[1]) {
        x=pst; y=u;
    }
    else if(up>=s[1] && dp[u]>=s[0]) {
        x=u; y=pst;
    }

    for(auto it : ad[u]) {
        if(it==pst) continue;
        dfs(it, u, up+dp[u]-dp[it]);
    }
}

vi ans;
void spread(int u, int in, int pst=-1) {
    s[in]--;
    ans[u]=in+1;
//    cout << u << " -> " << in << endl;
    if(s[in]==0) return;

//    cout << pst << "\n";
//     for(auto it : ad[5]){
//        cout << it << " ";
//     }
//     cout << endl;

    for(auto it : ad[u]) {
        if(it==pst) continue;
        spread(it, in, u);
        if(s[in]==0) return;
    }
}

vector<int> find_split(int N, int a, int b, int c, vector<int> p, vector<int> q) {
    n=N; m=p.size();
    vi tmp; tmp.pb(a); tmp.pb(b); tmp.pb(c);
    //sort(tmp.begin(), tmp.end());
    FOR(z, 0, 3) s[z]=tmp[z];

    FOR(i, 0, m) {
        ad[p[i]].pb(q[i]);
        ad[q[i]].pb(p[i]);
    }
    pre(0);
    dfs(0);

    FOR(i, 0, n) ans.pb(0);
    if(x==-1) return ans;

    FOR(i, 0, n) ans[i]=3;

    spread(x, 0, y);
    spread(y, 1, x);

//    cout << x << " " << y << ": " << rev << endl;
//    cout << s[0] << " " << s[1] << endl;

    return ans;
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 11
• Subtask 3: 22 / 22
• Subtask 4: 0 / 24
• Subtask 5: 0 / 36