Submission #723179

#	Time	Username	Problem	Language	Result	Execution time	Memory
723179		GrandTiger1729	Split the Attractions (IOI19_split)	C++17	29 / 100	104 ms	15960 KiB

split

#include "split.h"
#include <bits/stdc++.h>
using namespace std;

vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q){
	int m = p.size();
    vector<vector<int>> g(n);
    for (int i = 0; i < n - 1; i++){
        int u = p[i], v = q[i];
        g[u].push_back(v);
        g[v].push_back(u);
    }
    vector<int> sz(n), pa(n);
    {
        vector<bool> vis(n);
        function<void(int)> dfs = [&](int u){
            vis[u] = 1;
            sz[u] = 1;
            for (auto &v: g[u]){
                if (vis[v]) continue;
                dfs(v);
                sz[u] += sz[v];
                pa[v] = u;
            }
        };
        dfs(0);
    }
    auto get = [&](int x) -> int {
        if (x == 1) return a;
        if (x == 2) return b;
        if (x == 3) return c;
        return -1;
    };
    function<vector<int>(int, int, int, int)> draw = [&](int aa, int bb, int cc, int u) -> vector<int> {
        vector<bool> vis(n);
        vector<int> ret(n);
        function<void(int, int, int &)> dfs = [&](int u, int x, int &cnt){
            vis[u] = 1;
            if (cnt > 0){
                ret[u] = x;
                cnt--;
            }
            for (auto &v: g[u]){
                if (vis[v]) continue;
                dfs(v, x, cnt);
            }
        };
        vis[pa[u]] = 1;
        dfs(u, aa, *(new int(get(aa))));
        vis[pa[u]] = 0;
        dfs(0, bb, *(new int(get(bb))));
        for (int j = 0; j < n; j++)
            if (ret[j] == 0)
                ret[j] = cc;
        return ret;
    };
    for (int i = 0; i < n; i++){
        if (sz[i] >= a && n - sz[i] >= b)
            return draw(1, 2, 3, i);
        if (sz[i] >= b && n - sz[i] >= a)
            return draw(2, 1, 3, i);
        if (sz[i] >= b && n - sz[i] >= c)
            return draw(2, 3, 1, i);
        if (sz[i] >= c && n - sz[i] >= b)
            return draw(3, 2, 1, i);
        if (sz[i] >= c && n - sz[i] >= a)
            return draw(3, 1, 2, i);
        if (sz[i] >= a && n - sz[i] >= c)
            return draw(1, 3, 2, i);
    }
    return vector<int>(n, 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:6:6: warning: unused variable 'm' [-Wunused-variable]
    6 |  int m = p.size();
      |      ^

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