| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 208053 |
2020-03-09T21:35:41 Z |
AQT |
Towns (IOI15_towns) |
C++14 |
|
27 ms |
888 KB |
#include <towns.h>
#include <bits/stdc++.h>
using namespace std;
int dist[2][200];
int par[200], sz[200];
bool midset[200], chk[200];
int graph[200][200];
/*
int getDistance(int i, int j){
//cout << "? " << i << " " << j << endl;
//int k;
//cin >> k;
//return k;
return graph[i][j];
}
*/
int hubDistance(int N, int sub){
int d1 = 0, d2 = 0;
for(int i = 1; i<N; i++){
dist[0][i] = getDistance(0, i);
if(dist[0][i] > dist[0][d1]){
d1 = i;
}
}
for(int i = 0; i<N; i++){
dist[1][i] = getDistance(d1, i);
if(dist[1][i] > dist[1][d2]){
d2 = i;
}
}
int dia = dist[1][d2];
//cout << "diameter endpoints: " << d1 << " " << d2 << endl;
int ans = dia;
for(int i = 0; i<N; i++){
int k = (dist[0][d1] + dist[1][i] - dist[0][i])/2;
//cout << "which set?: " << i << " " << k << endl;
if(abs(ans-dia/2) > abs(k-dia/2)){
ans = k;
}
else if(dia%2 == 0 && abs(ans-dia/2) == abs(k-dia/2) && k < ans){
ans = k;
}
midset[i] = 0;
chk[i] = 0;
}
int d = ans;
ans = max(ans, dia-ans);
//cout << "ans: " << ans << "\n";
int lft = 0, rht = 0;
for(int i = 0; i<N; i++){
int k = (dist[0][d1] + dist[1][i] - dist[0][i])/2;
//cout << "which set again?: " << i << " " << k << endl;
//cout << dist[0][d1] << " " << dist[1][i] << " " << dist[0][i] << endl;
if(dia-k > k && dia-k > ans){
//cout << "lft: " << i << endl;
midset[i] = 1;
lft++;
}
else if(k > dia-k && k > ans){
//cout << "rht: " << i << endl;
midset[i] = 1;
rht++;
}
else if(dia-k == d){
chk[i] = 1;
}
//cout << dia-k << " " << k << "\n";
}
if(max(lft, rht) > N/2){
return -ans;
}
/*
vector<int> v, w;
for(int i =0 ; i<N; i++){
if(midset[i]){
par[i] = -1;
sz[i] = 0;
continue;
}
par[i] = i;
v.push_back(i);
sz[i] = 1;
}
int g = -1;
while(v.size()){
//cout << "next iteration: " << k << endl;
random_shuffle(v.begin(), v.end());
while(v.size() >= 2){
int n = v.back();
v.pop_back();
int m = v.back();
v.pop_back();
//cout << dist[1][n] + dist[1][m] - getDistance(n, m) << " " << 2*d << endl;
if(dist[1][n] + dist[1][m] - getDistance(n, m) > 2*d){
par[n] = -1;
sz[m] += sz[n];
w.push_back(m);
}
}
if(v.size() == 1 && w.empty()){
g = v[0];
break;
}
swap(v, w);
w.clear();
}
//cout << g << endl;
if(g != -1){
int cnt = 0;
for(int i = 0; i<N; i++){
if(par[i] == i && !midset[i]){
if(dist[1][i] + dist[1][g] - getDistance(i, g) > 2*d){
cnt += sz[i];
//cout << "sz: " << i << " " << sz[i] << endl;
}
}
}
//cout << cnt << endl;
if(cnt > N/2){
ans = -ans;
}
}
*/
/*
int g = -1, cnt = 0;
for(int i = 0; i<N; i++){
if(midset[i]){
continue;
}
if(cnt == 0){
g = i;
cnt = 1;
}
else if(dist[1][i] + dist[1][g] - getDistance(i, g) > 2*d){
cnt++;
}
else{
cnt--;
if(cnt == 0){
g = -1;
}
}
//cout << i << " " << cnt << endl;
}
//cout << "g: " << g << endl;
if(g != -1){
cnt = 0;
for(int i = 0; i<N; i++){
if(!midset[i] && dist[1][i] + dist[1][g] - getDistance(i, g) > 2*d){
cnt++;
}
}
//cout << cnt << endl;
if(cnt > N/2){
ans = -ans;
}
}
*/
//Attempt for 3/2 * N
/*
vector<int> v, w;
for(int i = 0; i<N; i++){
if(midset[i]){
v.push_back(-1);
if(w.size()){
v.push_back(w.back());
w.pop_back();
}
}
else if(v.empty() || dist[1][i] + dist[1][v.back()] - getDistance(i, v.back()) == 2*d){
//cout << i << endl;
v.push_back(i);
if(w.size()){
v.push_back(w.back());
w.pop_back();
}
}
else{
//cout << " " << i << endl;
w.push_back(i);
}
}
*/
/*
for(int i =0 ; i<v.size(); i++){
cout << v[i] << " ";
}
cout << endl;
for(int i = 0; i<w.size(); i++){
cout << w[i] << " ";
}
cout << endl;
*/
/*
int g = v.back();
v.pop_back();
//cout << "g: " << g << endl;
while(v.size()){
//cout << v.back() << endl;
if(g != -1 && v.back() != -1 && dist[1][v.back()] + dist[1][g] - getDistance(v.back(), g) > 2*d){
//cout << "hi" << endl;
//cout << v.back() << endl;
if(v.size() == 1){
w.push_back(v.back());
}
v.pop_back();
if(v.size()) {
v.pop_back();
}
}
else if(w.empty()){
return ans;
}
else{
v.pop_back();
w.pop_back();
}
}
if(w.size()){
//cout << w.size() << endl;
return -ans;
}
else{
return ans;
}
*/
vector<int> v, w;
//cout << "d: " << d << "\n";
for(int i = 0; i<N; i++){
if(midset[i]){
v.push_back(-1);
if(w.size()){
v.push_back(w.back());
w.pop_back();
}
continue;
}
/*
if(v.back() != -1){
cout << dist[1][v.back()] + dist[1][i] - getDistance(i, v.back()) << "\n";
}
*/
if(v.empty() || v.back() == -1){
v.push_back(i);
if(w.size()){
v.push_back(w.back());
w.pop_back();
}
}
else if((!chk[i] || !chk[v.back()]) && dist[1][v.back()] + dist[1][i] - getDistance(i, v.back()) == 2*d){
v.push_back(i);
if(w.size()){
v.push_back(w.back());
w.pop_back();
}
}
else if(chk[i] && chk[v.back()] && dist[1][i]-getDistance(i, v.back())+dist[1][v.back()] == 2*(dia-d)){
v.push_back(i);
if(w.size()){
v.push_back(w.back());
w.pop_back();
}
}
else{
w.push_back(i);
}
}
/*
for(int n : v){
cout << n << " ";
}
cout << "\n";
for(int n : w){
cout << n << " ";
}
cout << "\n";
*/
int m = v.back();
//cout << "m: " << m << " " << w.size() << " " << v.size() << "\n";
while(v.size() && w.size()){
if(m != -1 && v.back() != -1){
if(chk[m] && chk[v.back()] && dist[1][m]-getDistance(m, v.back())+dist[1][v.back()] > 2*(dia-d)){
v.pop_back();
if(v.size()){
v.pop_back();
}
else{
w.push_back(-1);
}
}
else if((!chk[m] || !chk[v.back()]) && dist[1][v.back()] + dist[1][m] - getDistance(m, v.back()) > 2*d){
v.pop_back();
if(v.size()){
v.pop_back();
}
else{
w.push_back(-1);
}
}
else{
v.pop_back();
w.pop_back();
}
}
else{
v.pop_back();
w.pop_back();
}
}
if(w.size()){
return -ans;
}
else{
return ans;
}
}
/*
int main(){
cin.sync_with_stdio(0);
cin.tie(0);
int tempN, sub, T;
cin >> sub >> T;
while(T--){
cin >> tempN;
for(int i =0 ; i<tempN; i++){
for(int j = 0; j<tempN; j++){
cin >> graph[i][j];
}
}
cout << hubDistance(tempN, sub) << "\n";
}
}
*/
Compilation message
towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:21:28: warning: unused parameter 'sub' [-Wunused-parameter]
int hubDistance(int N, int sub){
^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
24 ms |
376 KB |
Output is correct |
| 2 |
Correct |
20 ms |
376 KB |
Output is correct |
| 3 |
Correct |
5 ms |
376 KB |
Output is correct |
| 4 |
Correct |
27 ms |
376 KB |
Output is correct |
| 5 |
Correct |
25 ms |
376 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
23 ms |
376 KB |
Output is correct |
| 2 |
Correct |
20 ms |
376 KB |
Output is correct |
| 3 |
Correct |
25 ms |
376 KB |
Output is correct |
| 4 |
Correct |
25 ms |
380 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
20 ms |
376 KB |
Output is correct |
| 2 |
Correct |
25 ms |
376 KB |
Output is correct |
| 3 |
Correct |
5 ms |
256 KB |
Output is correct |
| 4 |
Correct |
26 ms |
888 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
25 ms |
376 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
22 ms |
376 KB |
Output is correct |
| 2 |
Correct |
25 ms |
376 KB |
Output is correct |
| 3 |
Correct |
24 ms |
380 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
20 ms |
376 KB |
Output is correct |
| 2 |
Correct |
25 ms |
376 KB |
Output is correct |
| 3 |
Correct |
25 ms |
376 KB |
Output is correct |
