Submission #607491

#	Time	Username	Problem	Language	Result	Execution time	Memory
607491		skittles1412	Friend (IOI14_friend)	C++17	46 / 100	145 ms	65536 KiB

friend

#include "bits/extc++.h"

using namespace std;

template <typename T>
void dbgh(const T& t) {
    cerr << t << endl;
}

template <typename T, typename... U>
void dbgh(const T& t, const U&... u) {
    cerr << t << " | ";
    dbgh(u...);
}

#ifdef DEBUG
#define dbg(...)                                              \
    cerr << "L" << __LINE__ << " [" << #__VA_ARGS__ << "]: "; \
    dbgh(__VA_ARGS__);
#else
#define dbg(...)
#define cerr   \
    if (false) \
    cerr
#endif

#define endl "\n"
#define long int64_t
#define sz(x) int((x).size())

const int maxn = 1e5 + 5;

int arr[maxn], memo[maxn][2];
vector<int> graph[maxn];

void pdfs(int u) {
    for (auto& v : graph[u]) {
        graph[v].erase(find(begin(graph[v]), end(graph[v]), u));
        pdfs(v);
    }
}

int dp(int u, bool cur) {
    int& ans = memo[u][cur];
    if (ans != -1) {
        return ans;
    }
    ans = cur * arr[u];
    for (auto& v : graph[u]) {
        if (cur) {
            ans += dp(v, false);
        } else {
            ans += max(dp(v, false), dp(v, true));
        }
    }
    return ans;
}

int findSample(int n, int _arr[], int host[], int protocol[]) {
    copy(_arr, _arr + n, arr);
    for (int i = 1; i < n; i++) {
        if (protocol[i] == 0 || protocol[i] == 2) {
            graph[i].push_back(host[i]);
        }
        if (protocol[i] == 1 || protocol[i] == 2) {
            graph[i].insert(graph[i].end(), begin(graph[host[i]]),
                            end(graph[host[i]]));
        }
        for (auto& a : graph[i]) {
            graph[a].push_back(i);
        }
    }
    if (n <= 10) {
        int ans = 0;
        for (int i = 0; i < (1 << n); i++) {
            int cans = 0;
            for (int j = 0; j < n; j++) {
                if ((i >> j) & 1) {
                    cans += arr[j];
                    for (auto& a : graph[j]) {
                        if ((i >> a) & 1) {
                            goto loop;
                        }
                    }
                }
            }
            ans = max(ans, cans);
        loop:;
        }
        return ans;
    }
    if (protocol[1] == 1) {
        for (auto& a : graph) {
            assert(!sz(a));
        }
        return accumulate(arr, arr + n, 0);
    } else if (protocol[1] == 2) {
        return *max_element(arr, arr + n);
    }
    pdfs(0);
    memset(memo, -1, sizeof(memo));
    return max(dp(0, false), dp(0, true));
}

• Subtask 1: 11 / 11
• Subtask 2: 8 / 8
• Subtask 3: 8 / 8
• Subtask 4: 19 / 19
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31