Submission #561130

#	Time	Username	Problem	Language	Result	Execution time	Memory
561130		two_sides	Reconstruction Project (JOI22_reconstruction)	C++17	100 / 100	2406 ms	27480 KiB

reconstruction

#include <bits/stdc++.h>

using namespace std;

const int N = 505;
const int M = 100005;

struct edge {
    int u, v, w;
    
    bool operator < (const edge &o) const {
        return w < o.w;
    }
};

struct disjoint {
    int par[N];
    
    void reset() {
        iota(par, par + N, 0);
    }
    
    int find(int u) {
        if (par[u] == u) return u;
        return par[u] = find(par[u]);
    }
    
    void unite(int u, int v) {
        par[find(v)] = find(u);
    }
    
    bool same(int u, int v) {
        return find(u) == find(v);
    }
} dsu;

edge grp[M], event[M * 3];

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int n, m; cin >> n >> m;
    for (int i = 0; i < m; i++)
        cin >> grp[i].u >> grp[i].v >> grp[i].w;
    sort(grp, grp + m);
    for (int i = 0; i < m; i++) {
        int l = i - 1, r = i + 1;
        dsu.reset();
        while (l >= 0) {
            dsu.unite(grp[l].u, grp[l].v);
            if (dsu.same(grp[i].u, grp[i].v)) break;
            l--;
        }
        dsu.reset();
        while (r < m) {
            dsu.unite(grp[r].u, grp[r].v);
            if (dsu.same(grp[i].u, grp[i].v)) break;
            r++;
        }
        event[i * 3] = {grp[i].w, -1, l < 0 ?
        -1 : (grp[l].w + grp[i].w + 1) / 2};
        event[i * 3 + 1] = {-2 * grp[i].w, 2, grp[i].w};
        event[i * 3 + 2] = {grp[i].w, -1, r == m ?
        1e9 + 1 : (grp[r].w + grp[i].w + 1) / 2};
    }
    sort(event, event + m * 3);
    int q; cin >> q;
    int mul = 0; long long add = 0;
    for (int i = 0, j = 0; i < q; i++) {
        long long cur; cin >> cur;
        while (j < 3 * m && event[j].w <= cur) {
            add += event[j].u;
            mul += event[j++].v;
        }
        cout << add + cur * mul << '\n';
    }
}

Compilation message (stderr)

reconstruction.cpp: In function 'int main()':
reconstruction.cpp:62:50: warning: narrowing conversion of '((r == m) ? (1.0e+9 + (double)1) : (double)((grp[r].edge::w + grp[i].edge::w + 1) / 2))' from 'double' to 'int' [-Wnarrowing]
   62 |         event[i * 3 + 2] = {grp[i].w, -1, r == m ?
      |                                           ~~~~~~~^
   63 |         1e9 + 1 : (grp[r].w + grp[i].w + 1) / 2};
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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