Submission #1093590

#	Time	Username	Problem	Language	Result	Execution time	Memory
1093590		_8_8_	Reconstruction Project (JOI22_reconstruction)	C++17	0 / 100	5097 ms	212704 KiB

reconstruction

#include <bits/stdc++.h>
    
using namespace std;
    
typedef long long ll;
const int  N = 1e6 + 12, MOD = (int)1e9 + 3;

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;
} 
void test() {
    cin >> n >> m;
    for(int i = 0;i < m; i++) {
        cin >> e[i][1] >> e[i][2] >> e[i][0];
    }
    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][1], e[i][2])) {
            cur.push_back(i);
            lst = i;
        }
    }
    tr.push_back(cur);
    for(int i = 0; i < m; i++) {
        bool bad = 0;
        for(int j:cur) {
            if(j == i) 
                bad = 1;
        }
        if(bad) continue;
        int j = id(e[i][1], e[i][2]);
        // return;
        int k = -1;
        for(int _ = 0; _ < (int)cur.size(); _++) {
            if(cur[_] == j) {
                k = _;
                break;
            }
        }
        cur.erase(cur.begin() + k);
        cur.push_back(i);
        tr.push_back(cur);
        // for(int j:cur) {
        //     cerr << j << ' ' << e[j][1] << ' ' << e[j][2] << '\n';
        // }
        // cout << i << ' ' << j << '\n';
        // cout << '\n';
    }
    int q;
    cin >> q;
    while(q--) {
        int x;
        cin >> x;
        ll res = cost(tr[0], x);
        for(auto c:tr) {
            res = min(res, cost(c, x));
        }
        cout << res << '\n';
    }
}

int 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:71:9: warning: variable 'lst' set but not used [-Wunused-but-set-variable]
   71 |     int lst = 0;
      |         ^~~

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