Submission #1093744

#	Time	Username	Problem	Language	Result	Execution time	Memory
1093744		_8_8_	Reconstruction Project (JOI22_reconstruction)	C++17	100 / 100	4663 ms	57580 KiB

reconstruction

#include <bits/stdc++.h>
    
using namespace std;
    
typedef long long ll;
const int  N = 1e6 + 12, MOD = (int)1e9 + 3;
    
#define int ll
int n, m, vis[N], timer = 0, p[N], f[N];
vector<array<int, 3>> e(N);
vector<vector<int>> tr;
vector<int> cur;
int id(int v, int u) {
    vector<vector<pair<int,int>>> g(n + 1);
    for(int i:cur) { 
        g[e[i][1]].push_back({e[i][2], i});
        g[e[i][2]].push_back({e[i][1], i});
    }
    queue<int> q;
    q.push(v);
    ++timer;
    vis[v] = timer;
    while(!q.empty()) {
        int x = q.front();
        q.pop();
        // cout << x << ' ' << p[x] << '\n';
        for(auto [to, i]:g[x]) {
            // cout << to << "x\n";
            if(vis[to] != timer) {
                vis[to] = timer;
                p[to] = x;
                f[to] = i;
                q.push(to);
            }
        }
    }
    int ret = 1e9;
    while(u != v) {
        ret = min(ret, f[u]);
        u = p[u];
        // cerr << u << ' ' << v << '\n';
    }
    return ret;
}
int P[N];
int get(int a) {
    if(P[a] == a) return a;
    return P[a] = get(P[a]);
}
bool merge(int a, int b) {
    a = get(a);
    b = get(b);
    if(a == b) return false;
    P[a] = b;
    return true;
}
ll cost(vector<int> &x, int val) {
    // cout << (int)x.size() << '\n';
    ll ret = 0;
    for(int i:x) {
        ret += abs(val - e[i][0]);
    }
    return ret;
} 
int l[N], r[N];
const int inf = (int)1e9;
void test() {
    cin >> n >> m;
    for(int i = 0;i < m; i++) {
        cin >> e[i][1] >> e[i][2] >> e[i][0];
        l[i] = 0, r[i] = inf;
    }
    iota(P + 1, P + n + 1, 1);
    sort(e.begin(), e.begin() + m);
    int lst = 0;
    for(int i = 0;i < m; i++) {
        if(merge(e[i][2], e[i][1])) {
            cur.push_back(i);
            continue;
        }
        int j = id(e[i][1], e[i][2]);
        ll val = (e[i][0] + e[j][0] + 1) / 2;
        l[i] = val;
        r[j] = val - 1;
        for(int k = 0; k < (int)cur.size(); k++) {
            if(cur[k] == j) {
                cur.erase(cur.begin() + k);
                break;
            }
        }
        cur.push_back(i);
    }
    vector<array<int, 3>> o;
    for(int i = 0; i < m; i++) {
        o.push_back({l[i], r[i], e[i][0]});
    }
    sort(o.begin(), o.end());
    multiset<int> L, R;
    multiset<pair<int, int>> st;
    ll _l = 0, _r = 0;
    int q;
    cin >> q;
    int it = 0;
    while(q--) {
        int x;
        cin >> x;
        ll res = 0;
        auto add = [&](int val) {
            if(val <= x) {
                _l += val;
                L.insert(val);
            } else {
                _r += val;
                R.insert(val);
            }
        };
        auto del = [&](int val) {
            if(L.find(val) != L.end()) {
                L.erase(L.find(val));
                _l -= val;
            } else {
                R.erase(R.find(val));
                _r -= val;
            }
        };
        auto f = [&](multiset<int> &t, ll s) {
            res += abs(s - x * 1ll * (int)t.size());
        };
        while(it < m && o[it][0] <= x) {
            st.insert({o[it][1], o[it][2]});
            add(o[it][2]);
            it++;
        }
        while(!st.empty()) {
            auto [d, e] = (*st.begin());
            if(d < x) {
                del(e);
                st.erase(st.find({d,e}));
            } else {
                break;
            }
        }
        while(!R.empty()) {
            int val = (*R.begin());
            // cerr << val << ' ' << x << '\n';
            if(val <= x) {
                R.erase(R.find(val));
                _r -= val;
                add(val);
            } else {
                break;
            }
        }
        f(L, _l);
        f(R, _r);
        cout << res << '\n';
    }
}
    
signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); 
    
    int t = 1; 
    // cin >> t;
    
    while(t--) 
        test();
    return 0;
}

Compilation message (stderr)

reconstruction.cpp: In function 'void test()':
reconstruction.cpp:75:9: warning: unused variable 'lst' [-Wunused-variable]
   75 |     int lst = 0;
      |         ^~~

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