Submission #1063687

#	Time	Username	Problem	Language	Result	Execution time	Memory
1063687		kkkkkkkk	Race (IOI11_race)	C++14	0 / 100	142 ms	262144 KiB

race

#include <bits/stdc++.h>

using namespace std;

vector<pair<int,int> > G[200005];
int is_removed[200005], subtree_size[200005], cekori[1000005];
int k;
int rez;
 
void get_subtree_size(int teme, int parent) {
	subtree_size[teme]=1;
	for (auto [next, dist]:G[teme]) {
		if (next==parent||is_removed[next]) continue;
		get_subtree_size(next, parent);
		subtree_size[teme]+=subtree_size[next];
	}
}
 
int get_centroid(int teme, int parent, int tree_size) {
	for (auto [next, dolz]:G[teme]) {
		if (next==parent||is_removed[next]) continue;
		if (subtree_size[next]*2>tree_size) 
		    return get_centroid(next, teme, tree_size);
    }
	return teme;
}

void check(int teme, int parent, int dolz, int depth) {
	if (dolz>k) return;
	if (cekori[k-dolz]!=-1) 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(int teme, int parent, int dolz, int depth) {
	if (dolz>k) return;
	if (cekori[dolz]==-1) 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 clear_cekori(int teme, int parent, int dolz) {
	if (dolz>k) return ;
	cekori[dolz]=-1;
	for (auto [next, dist]:G[teme]) {
		if (next==parent||is_removed[next]) continue;
		clear_cekori(next, teme, dolz+dist);
	}
}
 
void build_centroid_decomp(int teme=0){
	get_subtree_size(teme, -1);
	int centroid=get_centroid(teme, -1, subtree_size[teme]);
	cekori[0]=0;
	for (auto [next, dist]:G[centroid]) {
		if (is_removed[next]) continue;
		check(next, centroid, dist, 1);
		build(next, centroid, dist, 1);
	}
	for (auto [next, dist]:G[centroid]) {
		if (is_removed[next]) continue;
		clear_cekori(next, centroid, dist);
	}
	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[]){
	k=K;
	memset(cekori, -1, sizeof(cekori));
	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]});
	}
	rez=N+2;
	build_centroid_decomp();
	if (rez==N+2) rez=-1;
	return rez;
}

Compilation message (stderr)

race.cpp: In function 'void get_subtree_size(int, int)':
race.cpp:12:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   12 |  for (auto [next, dist]:G[teme]) {
      |            ^
race.cpp: In function 'int get_centroid(int, int, int)':
race.cpp:20:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   20 |  for (auto [next, dolz]:G[teme]) {
      |            ^
race.cpp: In function 'void check(int, int, int, int)':
race.cpp:31:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   31 |  for (auto [next, dist]:G[teme]) {
      |            ^
race.cpp: In function 'void build(int, int, int, int)':
race.cpp:41:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   41 |  for (auto [next, dist]:G[teme]) {
      |            ^
race.cpp: In function 'void clear_cekori(int, int, int)':
race.cpp:50:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   50 |  for (auto [next, dist]:G[teme]) {
      |            ^
race.cpp: In function 'void build_centroid_decomp(int)':
race.cpp:60:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   60 |  for (auto [next, dist]:G[centroid]) {
      |            ^
race.cpp:65:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   65 |  for (auto [next, dist]:G[centroid]) {
      |            ^
race.cpp:70:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   70 |  for (auto [next, dist]:G[centroid]) {
      |            ^

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