Submission #1044960

#	Time	Username	Problem	Language	Result	Execution time	Memory
1044960		vjudge1	Bridges (APIO19_bridges)	C++17	13 / 100	61 ms	19200 KiB

bridges

#pragma GCC optimize("unroll-loops,Ofast,O3")
#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define spc << " " <<
#define endl "\n"
#define all(x) x.begin(), x.end()
#define int long long
#define ii pair<long long,int>
#define vi vector<int>
#define vii vector<ii>
#define st first
#define nd second
#define inf 1e15
#define MOD 1000000007
#define MX 50005
using namespace std;

vii edges[MX];
int wei[2*MX];
int vis[MX];
int dfs(int node, int lim){
    vis[node]=1;
    int res=1;
    for(auto p:edges[node]){
        if(vis[p.st] || wei[p.nd]<lim) continue;
        res += dfs(p.st, lim);
    }
    return res;
}

int lie[MX], siz[MX];
int find(int x){
    if(lie[x]==x) return x;
    return lie[x] = find(lie[x]);
}
bool unite(int x, int y){
    x=find(x); y=find(y);
    if(x==y) return false;
    siz[x]+=siz[y];
    lie[y]=lie[x];
}

void solve(){
    int n,m,q; cin >> n >> m;
    vector<array<int, 3>> ws;
    for(int i=1; i<=m; i++){
        int a,b,c; cin >> a >> b >> c;
        edges[a].pb({b,i});
        edges[b].pb({a,i});
        wei[i]=c;
        ws.pb({c, a, b});
    }
    cin >> q;
    if(n<=1000 && m<=1000 && q<=10000){
        for(int i=1; i<=q; i++){
            int a,b,c; cin >> a >> b >> c;
            if(a==1){
                wei[b]=c;
            }
            else{
                for(int i=1; i<=n; i++) vis[i]=0;
                cout << dfs(b, c) << endl;
            }
        }
        return;
    }

    for(int i=1; i<=n; i++){
        lie[i]=i;
        siz[i]=1;
    }
    vector<array<int, 3>> qs;
    for(int i=1; i<=q; i++){
        int a,b,c; cin >> a >> b >> c;
        if(a==1) return;
        qs.pb({c,b,i});
    }
    int ans[q+1];
    sort(all(qs), greater<array<int, 3>>());
    sort(all(ws), greater<array<int, 3>>());
    int heh=0;
    for(auto p:qs){
        while(heh<ws.size() && ws[heh][0]>=p[0]){
            unite(ws[heh][1], ws[heh][2]);
            heh++;
        }
        ans[p[2]] = siz[find(p[1])];
    }
    for(int i=1; i<=q; i++) cout << ans[i] << endl;
}
 
 
signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);
    #ifdef Local
    freopen("in","r",stdin);
    freopen("out","w",stdout);
    #endif
 
    /*freopen("nondec.in","r",stdin);
    freopen("nondec.out","w",stdout);*/
 
    int t=1;
    //cin >> t;
    while(t--) solve();
}

Compilation message (stderr)

bridges.cpp: In function 'void solve()':
bridges.cpp:84:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |         while(heh<ws.size() && ws[heh][0]>=p[0]){
      |               ~~~^~~~~~~~~~
bridges.cpp: In function 'bool unite(long long int, long long int)':
bridges.cpp:41:11: warning: control reaches end of non-void function [-Wreturn-type]
   41 |     lie[y]=lie[x];
      |     ~~~~~~^~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 16
• Subtask 3: 0 / 17
• Subtask 4: 0 / 14
• Subtask 5: 0 / 13
• Subtask 6: 0 / 27