Submission #252420

#	Time	Username	Problem	Language	Result	Execution time	Memory
252420		Erkhemkhuu	Bridges (APIO19_bridges)	C++17	13 / 100	364 ms	36216 KiB

bridges

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define mp make_pair
#define F first
#define S second
typedef pair <ll, ll> pll;
const ll sN = 1005;
const ll N = 100005;
bool vis[N];
vector <vector <ll> > adj(N);
ll tree[N * 4], sz[N], par[N], out[N];
tuple <ll, ll, ll> brid[N];
vector <ll> wp[sN][sN];
struct trio {
    ll v, u, w;
} edges[N];
struct trio1 {
    ll v, w, ind;
} queries[N];
bool comp(trio &a, trio &b) {
    return (a.w > b.w);
}
bool comp1(trio1 &a, trio1 &b) {
    return (a.w > b.w);
}
void build(ll node, ll l, ll r) {
    if(l == r) {
        tree[node] = edges[l].w;
        return;
    }
    ll mid = (l + r) / 2;
    build(node * 2, l, mid);
    build(node * 2 + 1, mid + 1, r);
    tree[node] = min(tree[node * 2], tree[node * 2 + 1]);
    return;
}
void update(ll node, ll l, ll r, ll idx, ll val) {
    if(l == r) {
        tree[node] = val;
        return;
    }
    ll mid = (l + r) / 2;
    if(l <= idx && idx <= mid) update(node * 2, l, mid, idx, val);
    else update(node * 2 + 1, mid + 1, r, idx, val);
    tree[node] = min(tree[node * 2], tree[node * 2 + 1]);
    return;
}
ll get(ll x) {
    return ((x == par[x]) ? (x) : (par[x] = get(par[x])));
}
void unite(ll v, ll u) {
    ll parv = get(v);
    ll paru = get(u);
    if(parv == paru) return;
    if(sz[parv] < sz[paru]) swap(parv, paru);
    sz[parv] += sz[paru];
    par[paru] = parv;
    return;
}
void init() {
    for(ll i = 0; i < N; i++) {
        sz[i] = 1;
        par[i] = i;
    }
    return;
}
ll dfs(ll v, ll w) {
    ll ans = 1;
    vis[v] = true;
    for(auto &u: adj[v])
        for(auto &x: wp[v][u])
            if(!vis[u] && w <= x) ans += dfs(u, w);
    return ans;
}
int main() {
    ll n, m, i, v, u, w, q, t, l, r;
    bool flag = true;
    cin >> n >> m;
    flag &= (m != n - 1);
    for(i = 1; i <= m; i++) {
        cin >> v >> u >> w;
        adj[v].pb(u);
        adj[u].pb(v);
        flag &= (u == i + 1 && v == i);
        if(n <= 1000 && m <= 1000) {
            wp[v][u].pb(w);
            wp[u][v].pb(w);
            brid[i] = {v, u, wp[v][u].size() - 1};
        }
        edges[i] = {v, u, w};
    }
    cin >> q;
    if(n <= 1000 && m <= 1000 && q <= 10000) {
        while(q--) {
            cin >> t >> l >> r;
            if(t == 1) {
                auto temp = brid[l];
                ll x = get <0> (temp);
                ll y = get <1> (temp);
                ll z = get <2> (temp);
                wp[x][y][z] = wp[y][x][z] = r;
            }
            else {
                memset(vis, false, sizeof(vis));
                cout << dfs(l, r) << "\n";
            }
        }
        return 0;
    }
    bool flag1 = true;
    for(i = 1; i <= q; i++) {
        cin >> t >> l >> r;
        queries[i] = {l, r, i};
    }
    for(i = 1; i <= n; i++) {
        par[i] = i;
        sz[i] = 1;
    }
    sort(edges + 1, edges + m + 1, comp);
    sort(queries + 1, queries + q + 1, comp1);
    ll cur = 1;
    for(i = 1; i <= q; i++) {
        while(cur <= n && edges[cur].w >= queries[i].w) {
            unite(edges[cur].v, edges[i].u);
            cur++;
        }
        out[queries[i].ind] = sz[get(queries[i].v)];
    }
    for(i = 1; i <= q; i++)
        cout << out[i] << "\n";
    /*
    if(flag) {
        build(1, 1, n);
        while(q--) {
            cin >> t >> l >> r;
            if(t == 1) update(1, 1, n, l, r);
            else {

            }
        }
        return 0;
    }
    */
    return 0;
}

Compilation message (stderr)

bridges.cpp: In function 'int main()':
bridges.cpp:112:10: warning: unused variable 'flag1' [-Wunused-variable]
     bool flag1 = true;
          ^~~~~

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