Submission #313836

#	Time	Username	Problem	Language	Result	Execution time	Memory
313836		nikatamliani	Split the Attractions (IOI19_split)	C++14	0 / 100	1 ms	384 KiB

split

#include <bits/stdc++.h>
#include "split.h"
using namespace std;
const int N = 2e5 + 10;
int in[N], out[N], sub[N];
int timer, countA, countB, countC, aa, bb, cc;
#define vi vector < int >
int dfs(int x, int p, vector < vi > &edges) {
    in[x] = ++timer;
    sub[x] = 1;
    for(int to : edges[x]) {
        if(to != p) {
            sub[x] += dfs(to, x, edges);
        }
    }
    out[x] = ++timer;
    return sub[x];
}
int find_good(int x, int p, vector < vi > &edges) {
    int n = edges.size();
    for(int to : edges[x]) {
        if(to != p && sub[to] >= countA && sub[to] <= countA + countC) {
            return x;
        }
        if(to == p && n - sub[x] >= countA && n - sub[x] <= countA + countC) {
            return x;
        }
    }
    for(int to : edges[x]) {
        if(to != p && sub[to] > countA + countC) {
            return find_good(to, x, edges);
        }
    }
    return -1;
}
void find_children(int x, int p, int v, vi &ans, vector < vi > &edges) {
    if(in[x] >= in[v] && out[v] >= out[x]) {
        if(countA > 0) {
            ans[x] = aa; 
            --countA;
        }
    } else {
        if(countB > 0) {
            ans[x] = bb;
            --countB;
        }
    }
    for(int to : edges[x]) {
        if(to != p) {
            find_children(to, x, v, ans, edges);
        }
    }
}
vi find_split(int n, int a, int b, int c, vi p, vi q) {
    vector < vi > edges(n, vi(0, 0));
    vi ans(n);
    if(p.size() != n - 1) return ans;
    for(int i = 0; i < n - 1; ++i) {
        edges[p[i]].push_back(q[i]);
        edges[q[i]].push_back(p[i]);
    }
    if(a > b) swap(a, b), swap(aa, bb);
    if(b > c) swap(b, c), swap(bb, cc);
    if(a > b) swap(a, b), swap(aa, bb);
    int subTree = -1, good = -1;
    for(int i = 0, found = 0; i < n && !found; ++i) {
        timer = 0;
        dfs(i, -1, edges);
        for(int j = 0; j < n; ++j) {
            if(sub[j] >= a && sub[j] <= a + c) {
                subTree = j;
                good = i;
                found = 1;
                break;
            }
        }
    }
    if(subTree == -1) return ans;
    countA = a, countB = b, countC = c;
    // timer = 0; dfs(0, -1, edges);
    // int good = find_good(0, -1, edges); if(good == -1) return ans; 
    // timer = 0; dfs(good, -1, edges);
    // int subTree;
    // for(int i = 0; i < n; ++i) {
    //     if(sub[i] >= a && sub[i] <= a + c) {
    //         subTree = i;
    //     }
    // }
    find_children(good, -1, subTree, ans, edges);
    for(int i = 0; i < n; ++i) {
        if(ans[i] == 0) {
            ans[i] = cc;
        }
    }
    return ans;
}

Compilation message (stderr)

split.cpp: In function 'std::vector<int> find_split(int, int, int, int, std::vector<int>, std::vector<int>)':
split.cpp:57:17: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   57 |     if(p.size() != n - 1) return ans;
      |        ~~~~~~~~~^~~~~~~~

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