Submission #1064206

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064206		kkkkkkkk	Race (IOI11_race)	C++14	21 / 100	241 ms	12124 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;
map<int,int> cekori;
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;
}

void build(int teme, int parent, int dolz, int depth) {
    if (dolz>k) return;
    if (cekori.find(dolz)==cekori.end())
        cekori[dolz]=depth;
	else cekori[dolz]=min(cekori[dolz], depth);
    for (auto [next, dist]:G[teme]) {
        if (next==parent||is_removed[next]) continue;
        build(next, teme, dolz+dist, depth+1);
    }
}
 
void check(int teme, int parent, int dolz, int depth) {
    if (dolz>k) return;
    if (cekori.find(k-dolz)!=cekori.end())
        rez=min(rez, cekori[k-dolz]+depth);
    for (auto [next, dist]:G[teme]) {
        if (next==parent||is_removed[next]) continue;
        check(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]) {
        check(next, centroid, dist, 1);
        build(next, centroid, dist, 1);
    }
    cekori.clear();
    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;
    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 build(int, int, int, int)':
race.cpp:35:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   35 |     for (auto [next, dist]:G[teme]) {
      |               ^
race.cpp: In function 'void check(int, int, int, int)':
race.cpp:45:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   45 |     for (auto [next, dist]:G[teme]) {
      |               ^
race.cpp: In function 'void build_centroid_decomp(int)':
race.cpp:53:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   53 |     for (auto [next, dist]:G[centroid]) {
      |               ^
race.cpp:59:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   59 |     for (auto [next, dist]:G[centroid]) {
      |               ^

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