Submission #1037362

#	Time	Username	Problem	Language	Result	Execution time	Memory
1037362		onbert	Friend (IOI14_friend)	C++17	58 / 100	33 ms	16512 KiB

friend

#include "friend.h"
#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5;
int n, a[maxn], t[maxn];
vector<int> adj[maxn][4];

int dp[maxn][2];
void dfs(int u) {
    for (int i=0;i<=2;i++) for (int v:adj[u][i]) dfs(v);
    int pt = 0, def = 0;
    for (int v:adj[u][0]) def += dp[v][1];
    for (int v:adj[u][1]) def += dp[v][0];
    for (int v:adj[u][2]) def += dp[v][0];
    int val = def, cur = 0;
    for (int v:adj[u][0]) {
        for (;pt<adj[u][3].size() && adj[u][3][pt]<v; pt++) {
            int V = adj[u][3][pt];
            if (t[V]==1) cur += dp[V][1] - dp[V][0];
            else if (t[V]==2) cur = max(dp[V][1] - dp[V][0], cur);
        }
        val = max(def + cur, val);
        cur += dp[v][0] - dp[v][1];
    }
    for (;pt<adj[u][3].size(); pt++) {
        int V = adj[u][3][pt];
        if (t[V]==1) cur += dp[V][1] - dp[V][0];
        else if (t[V]==2) cur = max(dp[V][1] - dp[V][0], cur);
    }
    val = max(def + cur, val);

    dp[u][0] = 0;
    for (int v:adj[u][0]) dp[u][0] += dp[v][1];
    for (int v:adj[u][1]) dp[u][0] += dp[v][0];
    for (int v:adj[u][2]) dp[u][0] += dp[v][0];
    
    dp[u][1] = a[u];
    for (int v:adj[u][0]) dp[u][1] += dp[v][0];
    for (int v:adj[u][1]) dp[u][1] += dp[v][1];
    for (int v:adj[u][2]) dp[u][1] += dp[v][0];
    dp[u][1] = max({val, dp[u][0], dp[u][1]});
}

int findSample(int N, int confidence[], int host[], int T[]){
	n = N;
    for (int i=0;i<n;i++) a[i] = confidence[i];
    t[0] = T[0];
    for (int i=1;i<n;i++) t[i] = T[i];
    for (int i=1;i<n;i++) adj[host[i]][t[i]].push_back(i), adj[host[i]][3].push_back(i);
    dfs(0);
    // for (int j=0;j<=1;j++) {
    //     cout << j << endl;
    //     for (int i=0;i<n;i++) cout << dp[i][j] << " "; cout << endl;
    // }
    return dp[0][1];
}

Compilation message (stderr)

friend.cpp: In function 'void dfs(int)':
friend.cpp:17:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |         for (;pt<adj[u][3].size() && adj[u][3][pt]<v; pt++) {
      |               ~~^~~~~~~~~~~~~~~~~
friend.cpp:25:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |     for (;pt<adj[u][3].size(); pt++) {
      |           ~~^~~~~~~~~~~~~~~~~

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