Submission #1063658

#	Time	Username	Problem	Language	Result	Execution time	Memory
1063658		kkkkkkkk	Race (IOI11_race)	C++14	21 / 100	118 ms	21116 KiB

race

#include <bits/stdc++.h>

using namespace std;

vector<pair<int,int> > G[200005];
bool is_removed[200005];
int subtree_size[200005];
int rez=INT_MAX;
int cekori[1000005];
int k;

int get_subtree_size(int teme, int parent=-1) {
    subtree_size[teme]=1;
    for (auto [next, dolz]:G[teme]) {
        if (next==parent||is_removed[next]) continue;
        subtree_size[teme]+=get_subtree_size(next, teme);
    }
    return subtree_size[teme];
}

int get_centroid(int teme, int tree_size, int parent=-1) {
    for (auto [next, dolz]:G[teme]) {
        if (next==parent||is_removed[next]) continue;
        if (subtree_size[next]*2>tree_size)
            return get_centroid(next, tree_size, teme);
    }
    return teme;
}

queue<int> q;

void dfs1(int teme, int parent, int dolz, int depth) {
    if (dolz>k) return;
    if (cekori[dolz]>depth) cekori[dolz]=depth;
    else if (cekori[dolz]==-1) cekori[dolz]=depth, q.push(dolz);
    for (auto [next, dist]:G[teme]) {
        if (next==parent||is_removed[next]) continue;
        dfs1(next, teme, dolz+dist, depth+1);
    }
}

void dfs2(int teme, int parent, int dolz, int depth) {
    if (dolz>k) return;
    if (cekori[k-dolz]!=-1)
        rez=min(rez, depth+cekori[k-dolz]);
    for (auto [next, dist]:G[teme]) {
        if (next==parent||is_removed[next]) continue;
        dfs2(next, teme, dolz+dist, depth+1);
    }
}

void build_centroid_decomp(int teme=0) {
    int centroid=get_centroid(teme, get_subtree_size(teme));
    for (auto [next, dist]:G[centroid]) {
        dfs2(next, centroid, dist, 1);
        dfs1(next, centroid, dist, 1);
    }
    while (!q.empty()) {
        int br=q.front();
        q.pop();
        cekori[br]=-1;
    }
    is_removed[centroid]=1;
    for (auto [next, dist]:G[centroid]) {
        if (is_removed[next]) continue;
        build_centroid_decomp(next);
    }
}

int best_path(int n, int K, int H[][2], int L[]) {
    rez=INT_MAX;
    for (int i=0;i<n;i++)
        G[i].clear();
    memset(is_removed, 0, sizeof(is_removed));
    for (int i=0;i<n-1;i++) {
        G[H[i][0]].push_back({H[i][1], L[i]});
        G[H[i][1]].push_back({H[i][0], L[i]});
    }
    k=K;
    memset(cekori, -1, sizeof(cekori));
    build_centroid_decomp();
    if (rez==INT_MAX) return -1;
    return rez;
}

Compilation message (stderr)

race.cpp: In function 'int get_subtree_size(int, int)':
race.cpp:14:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   14 |     for (auto [next, dolz]:G[teme]) {
      |               ^
race.cpp: In function 'int get_centroid(int, int, int)':
race.cpp:22:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   22 |     for (auto [next, dolz]:G[teme]) {
      |               ^
race.cpp: In function 'void dfs1(int, int, int, int)':
race.cpp:36:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   36 |     for (auto [next, dist]:G[teme]) {
      |               ^
race.cpp: In function 'void dfs2(int, int, int, int)':
race.cpp:46:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   46 |     for (auto [next, dist]:G[teme]) {
      |               ^
race.cpp: In function 'void build_centroid_decomp(int)':
race.cpp:54:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   54 |     for (auto [next, dist]:G[centroid]) {
      |               ^
race.cpp:64:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   64 |     for (auto [next, dist]:G[centroid]) {
      |               ^

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57