Submission #1037302

#	Time	Username	Problem	Language	Result	Execution time	Memory
1037302		onbert	Friend (IOI14_friend)	C++17	8 / 100	23 ms	9820 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][2];

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

int findSample(int N, int confidence[], int host[], int protocol[]){
	n = N;
    for (int i=0;i<n;i++) a[i] = confidence[i];
    t[0] = 0;
    for (int i=1;i<n;i++) t[i] = protocol[i];
    for (int i=1;i<n;i++) adj[host[i]][t[i]].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 max(dp[0][0], dp[0][1]);
}

Compilation message (stderr)

friend.cpp: In function 'void dfs(int)':
friend.cpp:20:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |             while (pt<adj[u][1].size() && adj[u][1][pt] < v) cur += dp[adj[u][1][pt]][1] - dp[adj[u][1][pt]][0], pt++;
      |                    ~~^~~~~~~~~~~~~~~~~
friend.cpp:25:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |         while (pt<adj[u][1].size()) cur += dp[adj[u][1][pt]][1] - dp[adj[u][1][pt]][0], pt++;
      |                ~~^~~~~~~~~~~~~~~~~

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