Submission #777781

#	Time	Username	Problem	Language	Result	Execution time	Memory
777781		eltu0815	Reconstruction Project (JOI22_reconstruction)	C++14	31 / 100	5069 ms	23500 KiB

reconstruction

#include <bits/stdc++.h>
#define MAX 500005
#define MOD (ll)(1e9+7)
#define INF (ll)(1e18)
#define inf (1987654321)
 
using namespace std;    
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
 
int n, m, q;
int parent[505], par[505][10], mn[505][10], dep[505];
vector<pii> tree[505];
vector<pair<int, pii> > edge;
vector<vector<int> > MST;
vector<int> X;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    
    cin >> n >> m;
    edge.push_back({0, {0, 0}});
    for(int i = 1; i <= m; ++i) {
        int a, b, w; cin >> a >> b >> w;
        edge.push_back({w, {a, b}});
    }
    
    auto getParent = [&](auto&& self, int node) -> int {
        if(parent[node] == node) return node;
        else return parent[node] = self(self, parent[node]);
    };
    
    auto unionParent = [&](int u, int v) -> void {
        u = getParent(getParent, u), v = getParent(getParent, v);
        if(u > v) swap(u, v);
        parent[v] = u;
    };
    
    auto dfs = [&](auto&& self, int node, int p) -> void {
        dep[node] = dep[p] + 1;
        for(auto v : tree[node]) if(v.first != p) {
            mn[v.first][0] = v.second;
            par[v.first][0] = node;
            self(self, v.first, node);
        }
    };
    
    auto LCA = [&](int u, int v) {
        if(dep[u] < dep[v]) swap(u, v);
        int diff = dep[u] - dep[v], j = 0;
        while(diff) {
            if(diff & 1) u = par[u][j];
            diff >>= 1; ++j;
        }
        if(u == v) return u;
        for(int i = 9; i >= 0; --i) {
            if(par[u][i] != par[v][i]) {
                u = par[u][i];
                v = par[v][i];
            }
        }
        return par[u][0];
    };
    
    auto getmn = [&](int u, int p) -> int {
        int diff = dep[u] - dep[p], j = 0;
        int ret = inf;
        while(diff) {
            if(diff & 1) {
                ret = min(ret, mn[u][j]);
                u = par[u][j];
            }
            diff >>= 1; ++j;
        }
        return ret;
    };
    
    int x = 0;
    for(int i = 1; i <= m + 1; ++i) {
        if(x == inf) break;
        vector<int> tmp;
        priority_queue<pii> pq;
        for(int j = 1; j <= n; ++j) parent[j] = j, tree[j].clear();
        for(int j = 1; j <= n; ++j) for(int k = 0; k < 10; ++k) mn[j][k] = inf;
        for(int j = 1; j <= m; ++j) pq.push({-abs(edge[j].first - x), j});
        while(!pq.empty()) {
            int j = pq.top().second;
            int a = edge[j].second.first, b = edge[j].second.second;
            pq.pop();
            if(getParent(getParent, a) != getParent(getParent, b)) {
                tmp.push_back(j);
                unionParent(a, b);
                tree[a].push_back({b, edge[j].first});
                tree[b].push_back({a, edge[j].first});
            }
        }
        dfs(dfs, 1, 0);
        for(int k = 1; k < 10; ++k) for(int j = 1; j <= n; ++j) par[j][k] = par[par[j][k - 1]][k - 1];
        for(int k = 1; k < 10; ++k) for(int j = 1; j <= n; ++j) mn[j][k] = min(mn[j][k - 1], mn[par[j][k - 1]][k - 1]);
        
        X.push_back(x); MST.push_back(tmp);
        int mx = inf;
        for(int j = 1; j <= m; ++j) {
            int a = edge[j].second.first, b = edge[j].second.second;
            int p = LCA(a, b);
            int mnv = min(getmn(a, p), getmn(b, p)), x_opt = (mnv + edge[j].first)/2 + 1;
            if(mnv < edge[j].first && x_opt > x) mx = min(mx, x_opt);
        }
        x = mx;
    }
    
    cin >> q;
    int i = 0;
    while(q--) {
        int x; cin >> x;
        while(i + 1 < (int)X.size() && X[i + 1] <= x) ++i;
        ll ans = 0;
        for(auto j : MST[i]) ans += 1ll * abs(edge[j].first - x);
        cout << ans << '\n';
    }
    return 0;
}
    

• Subtask 1: 3 / 3
• Subtask 2: 0 / 4
• Subtask 3: 0 / 7
• Subtask 4: 28 / 28
• Subtask 5: 0 / 35
• Subtask 6: 0 / 23