| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 585080 | Mazaalai | Friend (IOI14_friend) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#include "friend.h"
#define LINE "------------\n"
#define ALL(x) x.begin(),x.end()
#define LLA(x) x.rbegin(),x.rend()
#define pb push_back
using namespace std;
using PII = pair <int, int>;
using ll = long long;
// Find out best sample
/*
0 for IAmYourFriend,
1 for MyFriendsAreYourFriends,
2 for WeAreYourFriends.
*/
const int N = 1e3 + 5;
bool isFriend[N][N];
vector <int> paths[N]
int dp[N][2], nums[N];
void IAmYourFriend(int x, int y) {
if (x > y) swap(x, y);
paths[x].pb(y);
isFriend[x][y] = isFriend[y][x] = 1;
}
void MyFriendsAreYourFriends(int x, int y) {
for (int i = 0; i < N; i++)
if (isFriend[y][i]) IAmYourFriend(el, x);
}
void WeAreYourFriends(int x, int y) {
MyFriendsAreYourFriends(x, y);
IAmYourFriend(x, y);
}
int solve(int pos, int state) {
int& res = dp[pos][state];
if (res != -1) return res;
res = state * nums[pos];
for (auto el : paths[pos]) {
if (state) res += solve(pos, state^1);
else res += max(solve(el, state), solve(el, state^1));
}
return res;
}
int findSample(int n, int _nums[], int host[], int type[]){
int ans = 0;
for (int i = 0; i < n; i++) nums[i] = _nums[i];
if (n <= 10) {
for (int i = 1; i < n; i++) {
if (type[i] == 0) IAmYourFriend(i, host[i]);
else if (type[i] == 1) MyFriendsAreYourFriends(i, host[i]);
else WeAreYourFriends(i, host[i]);
}
for (int i = 0; i < (1<<n); i++) {
vector <int> ids;
for (int j = 0; j < n; j++) {
if (i & (1<<j)) ids.pb(j);
}
bool no = 0;
for (auto el : ids)
for (auto el1 : ids) {
no |= isFriend[el][el1];
}
if (no) continue;
int sum = 0;
for (auto el : ids) {
// cout << el <<" ";
sum += nums[el];
}
// cout << ": " << sum << '\n';
ans = max(ans, sum);
}
} else if (type[1] == 0) {
for (int i = 1; i < n; i++)
IAmYourFriend(i, host[i]);
memset(dp, -1, sizeof(dp));
ans = max(
solve(1, 0);
solve(1, 1);
);
} else if (type[1] == 1) {
// cout << "B\n";
for (int i = 0; i < n; i++) ans += nums[i];
} else if (type[1] == 2) {
// cout << "C\n";
for (int i = 0; i < n; i++) ans = max(ans, nums[i]);
}
return ans;
}