Submission #1097584

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097584		vjudge1	Museum (CEOI17_museum)	C++17	100 / 100	553 ms	746576 KiB

museum

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define pa pair<int, int>
#define pall pair<ll, int>
#define fi first
#define se second
#define TASK "test"
#define Size(x) (int) x.size()
#define all(x) x.begin(), x.end()
using namespace std;

template<typename T1, typename T2> bool mini (T1 &a, T2 b) {if(a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2> bool maxi (T1 &a, T2 b) {if(a < b) a = b; else return 0; return 1;}

const int MOD = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e4 + 7;
const ll oo = (ll) 1e9 + 69;

int n, k, x, u, v, w, sz[maxn], dp[maxn][maxn][2], f[2][maxn][2];
vector<pa> g[maxn];

void dfs(int u, int par) {
    for(auto e:g[u]) {
        int v = e.fi;
        if(v == par) continue;
        dfs(v, u);
    }

    for(int i = 0; i < 2; i++) {
        for(int j = 0; j <= k; j++) {
            for(int t = 0; t < 2; t++) {
                f[i][j][t] = oo;
            }
        }
    }
    f[0][1][1] = 0;
    //f[0][1][0] = 0;
    // f[0][0][0] = 0;
    // f[0][0][1] = 0;
    sz[u] = 1;

    for(int i = 1; i <= Size(g[u]); i++) {
        int v = g[u][i - 1].fi;
        int w = g[u][i - 1].se;
        if(v == par) {
            for(int j = 0; j <= sz[u]; j++) {
                for(int t = 0; t < 2; t++) {
                    f[i & 1][j][t] = f[i & 1 ^ 1][j][t];
                }
            }
            continue;
        }

        for(int j = 0; j <= sz[u]; j++) {
            for(int pre = 0; pre <= sz[v]; pre++) {
                int cost = w * (pre > 0);
                mini(f[i & 1][j + pre][0], f[i & 1 ^ 1][j][0] + dp[v][pre][1] + 2 * cost);
                mini(f[i & 1][j + pre][0], f[i & 1 ^ 1][j][1] + dp[v][pre][0] + cost);
                mini(f[i & 1][j + pre][1], f[i & 1 ^ 1][j][1] + dp[v][pre][1] + 2 * cost);
            }
        }
        sz[u] += sz[v];
    }

    for(int i = 0; i <= k; i++) {
        for(int t = 0; t < 2; t++) {
            dp[u][i][t] = f[Size(g[u]) & 1][i][t];
        }
    }
    dp[u][0][0] = dp[u][0][1] = 0;
    dp[u][1][0] = 0;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    //freopen(TASK".inp", "r", stdin);
    //freopen(TASK".out", "w", stdout);

    cin>>n>>k>>x;
    for(int i = 1; i < n; i++) {
        cin>>u>>v>>w;
        g[u].pb({v, w});
        g[v].pb({u, w});
    }
    dfs(x, 0);
    cout<<min(dp[x][k][0], dp[x][k][1]);
    return 0;
}

Compilation message (stderr)

museum.cpp: In function 'void dfs(int, int)':
museum.cpp:51:42: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   51 |                     f[i & 1][j][t] = f[i & 1 ^ 1][j][t];
      |                                        ~~^~~
museum.cpp:60:48: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   60 |                 mini(f[i & 1][j + pre][0], f[i & 1 ^ 1][j][0] + dp[v][pre][1] + 2 * cost);
      |                                              ~~^~~
museum.cpp:61:48: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   61 |                 mini(f[i & 1][j + pre][0], f[i & 1 ^ 1][j][1] + dp[v][pre][0] + cost);
      |                                              ~~^~~
museum.cpp:62:48: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   62 |                 mini(f[i & 1][j + pre][1], f[i & 1 ^ 1][j][1] + dp[v][pre][1] + 2 * cost);
      |                                              ~~^~~

• Subtask 1: 20 / 20
• Subtask 2: 25 / 25
• Subtask 3: 35 / 35
• Subtask 4: 20 / 20