# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
102717 |
2019-03-27T08:19:07 Z |
wxh010910 |
Towns (IOI15_towns) |
C++17 |
|
33 ms |
1144 KB |
#include <bits/stdc++.h>
#include "towns.h"
using namespace std;
int hubDistance(int N, int sub) {
vector<vector<int>> dist(2, vector<int>(N, 0));
int root = 0, left = 0, right = 0;
for (int i = 0; i < N; ++i) {
if (i != root) {
dist[0][i] = getDistance(root, i);
if (dist[0][i] > dist[0][left]) {
left = i;
}
}
}
for (int i = 0; i < N; ++i) {
if (i != left) {
dist[1][i] = getDistance(left, i);
if (dist[1][i] > dist[1][right]) {
right = i;
}
}
}
int limit = (dist[0][left] - dist[0][right] + dist[1][right]) >> 1;
vector<int> from(N, 0), all;
for (int i = 0; i < N; ++i) {
from[i] = (dist[1][i] - dist[0][i] + dist[0][left]) >> 1;
if (from[i] <= limit) {
all.push_back(from[i]);
}
}
sort(all.begin(), all.end());
all.erase(unique(all.begin(), all.end()), all.end());
int ans = dist[1][right];
for (auto p : all) {
ans = min(ans, max(p, dist[1][right] - p));
}
int another = root = -1;
for (auto p : all) {
if (max(p, dist[1][right] - p) == ans) {
if (root == -1) {
root = p;
} else {
another = p;
}
}
}
if (root != -1 && another != -1) {
int size_left = 0;
for (int i = 0; i < N; ++i) {
if (from[i] <= root) {
++size_left;
}
}
if (size_left == N - size_left) {
return ans;
} else if (size_left < N - size_left) {
root = another;
}
}
int last = -1, cur = 0;
auto is_same = [&](int x, int y) {
if (from[x] == root && from[y] == root) {
return dist[0][x] + dist[1][y] > getDistance(x, y) + dist[0][left];
} else {
return (from[x] < root && from[y] < root) || (from[x] > root && from[y] > root);
}
};
vector<int> type(N);
for (int i = 0; i < N; ++i) {
if (!cur) {
last = i;
++cur;
type[i] = 0;
} else if (is_same(i, last)) {
++cur;
type[i] = 1;
} else {
--cur;
type[i] = 2;
}
}
if (!cur) {
return ans;
}
int best = last, total = cur = 0;
bool same = false;
for (int i = 0; i < N; ++i) {
if (!type[i]) {
if (is_same(best, i)) {
same = true;
++total;
}
++cur;
} else if (type[i] == 1) {
if (same) {
++total;
}
++cur;
} else {
if (is_same(best, i)) {
++total;
}
if (!--cur) {
same = false;
}
}
}
if (total > N >> 1) {
return -ans;
} else {
return ans;
}
}
Compilation message
towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:6:28: warning: unused parameter 'sub' [-Wunused-parameter]
int hubDistance(int N, int sub) {
^~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
17 ms |
1096 KB |
Output is correct |
2 |
Correct |
16 ms |
896 KB |
Output is correct |
3 |
Correct |
2 ms |
256 KB |
Output is correct |
4 |
Correct |
19 ms |
896 KB |
Output is correct |
5 |
Correct |
20 ms |
896 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
33 ms |
900 KB |
Output is correct |
2 |
Correct |
14 ms |
768 KB |
Output is correct |
3 |
Correct |
19 ms |
896 KB |
Output is correct |
4 |
Correct |
22 ms |
896 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
29 ms |
860 KB |
Output is correct |
2 |
Correct |
20 ms |
1024 KB |
Output is correct |
3 |
Correct |
2 ms |
384 KB |
Output is correct |
4 |
Correct |
21 ms |
896 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
21 ms |
1144 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
30 ms |
852 KB |
Output is correct |
2 |
Correct |
18 ms |
896 KB |
Output is correct |
3 |
Correct |
18 ms |
896 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
860 KB |
Output is correct |
2 |
Correct |
20 ms |
1016 KB |
Output is correct |
3 |
Correct |
24 ms |
896 KB |
Output is correct |