Submission #877721

#	Time	Username	Problem	Language	Result	Execution time	Memory
877721		hafo	Factories (JOI14_factories)	C++14	100 / 100	2866 ms	155948 KiB

factories

#include"factories.h"
#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 = 19;
const int maxn = 5e5 + 7;
const ll oo = 1e18 + 69;

int n, q, mark[maxn], A[maxn], B[maxn], D[maxn], X[maxn], Y[maxn], S, T, st[maxn], en[maxn], timer = 0, cur;
vector<pa> g[maxn];
ll dp[maxn][2], f[maxn], ans;
vector<int> node;

bool cmp(int i, int j) {
    return st[i] < st[j];
}

struct LCA {
    int p[LOG][maxn], dep[maxn];

    void dfs(int u, int par) {
        for(auto e:g[u]) {
            int v = e.fi, w = e.se;
            if(v == par) continue;
            dep[v] = dep[u] + 1;
            p[0][v] = u;
            dfs(v, u);
        }
    }

    void init() {
        memset(p, -1, sizeof p);
        dep[0] = 0;
        dfs(0, 0);
        for(int i = 1; i < LOG; i++) {
            for(int u = 0; u < n; u++) p[i][u] = p[i - 1][p[i - 1][u]];
        }
    }

    int get_lca(int u, int v) {
        if(dep[u] < dep[v]) swap(u, v);
        int k = dep[u] - dep[v];
        for(int i = 0; i < LOG; i++) 
            if((k >> i) & 1) u = p[i][u];

        if(u == v) return u;

        for(int i = LOG - 1; i >= 0; i--) 
            if(p[i][u] != p[i][v]) {
                u = p[i][u];
                v = p[i][v];
            }
        return p[0][u];
    }

} lca;

void dfs(int u, int par) {
    st[u] = ++timer;
    for(auto e:g[u]) {
        int v = e.fi, w = e.se;
        if(v == par) continue;
        f[v] = f[u] + w;
        dfs(v, u);
    }
    en[u] = timer;
}

void dfs2(int u) {
    if(mark[u] == 1) dp[u][0] = 0;
    if(mark[u] == 2) dp[u][1] = 0;
    if(mark[u] == 3) {
        dp[u][0] = 0;
        dp[u][1] = 0;
    }
    mark[u] = 0;
    cur++;
    while(cur < Size(node)) {
        int v = node[cur];
        if(st[u] <= st[v] && st[v] <= en[u]) {
            dfs2(v);
            mini(ans, dp[u][0] + dp[v][1] + f[v] - f[u]);
            mini(ans, dp[u][1] + dp[v][0] + f[v] - f[u]);
            mini(dp[u][0], dp[v][0] + f[v] - f[u]);
            mini(dp[u][1], dp[v][1] + f[v] - f[u]);
        } else break;
    }
}

void Init(int N, int A[], int B[], int D[]){
    n = N;
    for(int i = 0; i < n - 1; i++) {
        g[A[i]].pb({B[i], D[i]});
        g[B[i]].pb({A[i], D[i]});
    }       

    for(int i = 0; i < n; i++) 
        for(int j = 0; j < 2; j++) dp[i][j] = oo;
    dfs(0, 0);
    lca.init(); 
}

long long Query(int S, int X[], int T, int Y[]){
    for(int i = 0; i < S; i++) {
        node.pb(X[i]);
        mark[X[i]] = 1;
    }
    for(int i = 0; i < T; i++) {
        node.pb(Y[i]);
        if(mark[Y[i]] == 1) mark[Y[i]] = 3;
        else if(mark[Y[i]] == 0) mark[Y[i]] = 2;
    }

    sort(all(node), cmp);
    for(int i = 1; i < S + T; i++) {
        int par = lca.get_lca(node[i], node[i - 1]);
        if(!mark[par]) {
            mark[par] = 4;
            node.pb(par);
        }
    }

    if(!mark[0]) {
        mark[0] = 4;
        node.pb(0);
    }

    sort(all(node), cmp);
    cur = 0;
    ans = oo;
    dfs2(0);

    for(auto i:node) {
        mark[i] = 0;
        dp[i][0] = dp[i][1] = oo;
    }
    node.clear();
    return ans;
}

Compilation message (stderr)

factories.cpp: In member function 'void LCA::dfs(int, int)':
factories.cpp:37:27: warning: unused variable 'w' [-Wunused-variable]
   37 |             int v = e.fi, w = e.se;
      |                           ^

• Subtask 1: 15 / 15
• Subtask 2: 18 / 18
• Subtask 3: 67 / 67