Submission #411306

#	Time	Username	Problem	Language	Result	Execution time	Memory
411306		couplefire	Training (IOI07_training)	C++17	100 / 100	17 ms	4724 KiB

training

#include <bits/stdc++.h>
using namespace std;

const int N = 1005;
const int INF = 0x3f3f3f3f;

int n, m;
vector<int> adj[N], child[N], paths[N];
vector<array<int, 3>> edges, tmpe;
int dep[N], dp[N][1<<10], tin[N], tout[N], timer = -1, up[N][20];
int id[N], iid[10], lol[10][10];
int ans;

void dfs1(int v, int p){
    tin[v] = ++timer;
    up[v][0] = p;
    for(int i = 1; i<20; i++) up[v][i] = up[up[v][i-1]][i-1];
    for(auto u : adj[v]){
        if(u == p) continue;
        dep[u] = dep[v]+1;
        child[v].push_back(u);
        dfs1(u, v);
    }
    tout[v] = timer;
}

bool isPar(int u, int v){
    return tin[u] <= tin[v] && tout[v] <= tout[u];
}

int LCA(int u, int v){
    if(isPar(u, v)) return u;
    if(isPar(v, u)) return v;
    for(int i = 19; i>=0; i--)
        if(!isPar(up[u][i], v)) u = up[u][i];
    return up[u][0];
}

void dfs2(int v, int p){
    for(auto u : adj[v]){
        if(u == p) continue;
        dfs2(u, v);
    }
    int cnt = 0;
    for(auto u : child[v])
        id[u] = cnt, iid[cnt++] = u;
    memset(lol, -1, sizeof lol);
    for(int i : paths[v]){
        auto e = edges[i];
        int a = e[0], b = e[1], w = e[2];
        if(dep[a] > dep[b]) swap(a, b);
        int ca = -1, cb = -1;
        int res = w;
        while(a != v){
            if(ca == -1) res += dp[a][(1<<child[a].size())-1];
            else res += dp[a][((1<<child[a].size())-1)^(1<<id[ca])];
            ca = a, a = up[a][0];
        }
        while(b != v){
            if(cb == -1) res += dp[b][(1<<child[b].size())-1];
            else res += dp[b][((1<<child[b].size())-1)^(1<<id[cb])];
            cb = b, b = up[b][0];
        }
        if(ca == -1) ca = cb;
        ca = id[ca], cb = id[cb];
        if(ca > cb) swap(ca, cb);
        lol[ca][cb] = max(lol[ca][cb], res);
    }
    memset(dp[v], -1, sizeof(int)*(1<<cnt));
    dp[v][0] = 0;
    for(int mask = 0, end = (1<<cnt); mask<end; ++mask){
        int tmp = 0;
        for(int i = 0; i<cnt; i++){
            if(!(mask&(1<<i))) continue;
            tmp += dp[iid[i]][(1<<child[iid[i]].size())-1];
            for(int j = i; j<cnt; j++){
                if(!(mask&(1<<j))) continue;
                int mi = ((1<<cnt)-1)^(1<<i), mj = ((1<<cnt)-1)^(1<<j);
                if(dp[v][mask&mi&mj] == -1) continue;
                dp[v][mask] = max(dp[v][mask], lol[i][j]+dp[v][mask&mi&mj]);
            }
        }
        dp[v][mask] = max(dp[v][mask], tmp);
    }
}

int main(){
    // freopen("a.in", "r", stdin);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin >> n >> m;
    for(int i = 0; i<m; i++){
        int a, b, w; cin >> a >> b >> w; --a; --b;
        if(!w)
            adj[a].push_back(b),
            adj[b].push_back(a);
        else 
            edges.push_back({a, b, w});
    }
    dfs1(0, 0);
    m = edges.size();
    for(int i = 0; i<m; i++){
        int a = edges[i][0], b = edges[i][1], w = edges[i][2];
        ans += w;
        if(dep[a]%2 != dep[b]%2) continue;
        tmpe.push_back(edges[i]);
    }
    swap(tmpe, edges);
    m = edges.size();
    for(int i = 0; i<m; i++){
        auto e = edges[i];
        int a = e[0], b = e[1];
        paths[LCA(a, b)].push_back(i);
    }
    dfs2(0, 0);
    cout << ans-dp[0][(1<<child[0].size())-1] << endl;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 7 / 7
• Subtask 5: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 9 / 9
• Subtask 10: 9 / 9
• Subtask 11: 9 / 9