Submission #673029

#	Time	Username	Problem	Language	Result	Execution time	Memory
673029		JooDdae	Bridges (APIO19_bridges)	C++17	100 / 100	2088 ms	9908 KiB

bridges

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
 
int n, m, q, p[50050], sz[50050], ans[100100];
bool chk[100100], chk2[100100];
 
stack<array<int, 2>> st;
 
int find(int a) {
    if(a == p[a]) return a;
    return find(p[a]);
}
 
bool merge(int a, int b) {
    // cout << a << "+" << b << "\n";
    a = find(a), b = find(b);
    if(a == b) return false;
    if(sz[a] < sz[b]) swap(a, b);
 
    p[b] = a, sz[a] += sz[b];
    st.push({a, b});
    return true;
}
 
int main(){
    cin.tie(0)->sync_with_stdio(0);
    cin >> n >> m;
    vector<array<int, 3>> E(m);
    for(auto &[z, x, y] : E) cin >> x >> y >> z;
 
    cin >> q;
    int s = 1000;
 
    for(int b=0;b<q;b+=s) {
        int k = min(b+s, q) - b;
 
        for(int i=1;i<=n;i++) p[i] = i, sz[i] = 1;
        while(!st.empty()) st.pop();
 
        vector<array<int, 3>> v, v2;
        for(int i=0;i<k;i++) {
            int q, x, y; cin >> q >> x >> y;
 
            if(q == 2) v.push_back({y, x, i});
            else x--, v2.push_back({i, x, y}), chk[x] = 1;
        }
        sort(v.rbegin(), v.rend());
 
        vector<array<int, 3>> e;
        for(int i=0;i<m;i++) if(!chk[i]) e.push_back(E[i]);
        sort(e.rbegin(), e.rend());
 
        int j = 0;
        for(auto [y, x, i] : v) {
            while(j < e.size() && e[j][0] >= y) merge(e[j][1], e[j][2]), j++;
 
            int r = 0;
            while(r < v2.size() && v2[r][0] < i) r++;
            // cout << r << "\n";
 
            int cnt = 0;
            for(int u=r-1;u>=0;u--) if(!chk2[v2[u][1]]) {
                int id = v2[u][1]; chk2[id] = 1;
                if(v2[u][2] >= y) cnt += merge(E[id][1], E[id][2]);
            }
            for(auto [i, id, w] : v2) if(!chk2[id] && E[id][0] >= y) chk2[id] = 1,  cnt += merge(E[id][1], E[id][2]);
 
            ans[b+i] = sz[find(x)];
 
            while(cnt--) {
                auto [x, y] = st.top(); st.pop();
                p[y] = y, sz[x] -= sz[y];
            }
            for(auto [i, id, w] : v2) chk2[id] = 0;
        }
 
        // cout << "reset\n";
        for(auto [i, x, y] : v2) E[x][0] = y, chk[x] = 0;
    }
    
    // cout << "----------\n";
 
    for(int i=0;i<q;i++) if(ans[i]) cout << ans[i] << "\n";
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:56:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |             while(j < e.size() && e[j][0] >= y) merge(e[j][1], e[j][2]), j++;
      |                   ~~^~~~~~~~~~
bridges.cpp:59:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |             while(r < v2.size() && v2[r][0] < i) r++;
      |                   ~~^~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 16 / 16
• Subtask 3: 17 / 17
• Subtask 4: 14 / 14
• Subtask 5: 13 / 13
• Subtask 6: 27 / 27