제출 #1019883

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1019883		NValchanov	친구 (IOI14_friend)	C++17	컴파일 에러	0 ms	0 KiB

friend

#include <bits/stdc++.h>
#include "friend.h"

using namespace std;

typedef long long ll;

const int MAXN = 1e5 + 10;

vector < int > adj[MAXN];
int dp[MAXN][2];
bool visited[MAXN];

void build_graph(int n, int p[], int type[])
{
    for(int i = 1; i < n; i++)
    {
        if(type[i] == 0)
        {
            adj[i].push_back(p[i]);
            adj[p[i]].push_back(i);
        }
        else if(type[i] == 1)
        {
            for(int v : adj[p[i]])
            {
                adj[v].push_back(i);
                adj[i].push_back(v);
            }
        }
        else if(type[i] == 2)
        {
            for(int v : adj[p[i]])
            {
                adj[v].push_back(i);
                adj[i].push_back(v);
            }

            adj[i].push_back(p[i]);
            adj[p[i]].push_back(i);
        }
    }
}

int bruteforce(int n, int c[])
{
    int ans = 0;

    for(int mask = 1; mask < (1 << n); mask++)
    {
        bool lampa = false;

        for(int i = 0; i < n; i++)
        {
            if(mask & (1 << i))
            {
                for(int v : adj[i])
                {
                    if(mask & (1 << v))
                        lampa = true;
                }
            }
        }

        if(lampa)
            continue;

        int sum = 0;

        for(int i = 0; i < n; i++)
        {
            if(mask & (1 << i))
                sum += c[i];
        }

        ans = max(ans, sum);
    }

    return ans;
}

void dfs(int u, int par, int c[])
{
    visited[u] = true;
    dp[u][1] = c[u];

    for(int v : adj[u])
    {
        if(v == par)
            continue;

        dfs(v, u, c);

        dp[u][0] += max(dp[v][0], dp[v][1]);
        dp[u][1] += dp[v][0];
    }
}

void solve_dp(int n, int c[])
{
    int ans = 0;

    for(int i = 0; i < n; i++)
    {
        if(!visited[i])
        {
            dfs(i, i, c);
            ans += max(dp[i][0], dp[i][1]);
        }
    }

    return ans;
}

int findSample(int n, int c[], int p[], int type[])
{
    build_graph(n, p, type);

    if(n <= 10)
        bruteforce(n, c[]);
    else
        solve_dp(n, c[]);
}

컴파일 시 표준 에러 (stderr) 메시지

friend.cpp: In function 'void solve_dp(int, int*)':
friend.cpp:112:12: error: return-statement with a value, in function returning 'void' [-fpermissive]
  112 |     return ans;
      |            ^~~
friend.cpp: In function 'int findSample(int, int*, int*, int*)':
friend.cpp:120:25: error: expected primary-expression before ']' token
  120 |         bruteforce(n, c[]);
      |                         ^
friend.cpp:122:23: error: expected primary-expression before ']' token
  122 |         solve_dp(n, c[]);
      |                       ^
friend.cpp:123:1: warning: no return statement in function returning non-void [-Wreturn-type]
  123 | }
      | ^