Submission #773488

#	Time	Username	Problem	Language	Result	Execution time	Memory
773488		Magikarp4000	Bridges (APIO19_bridges)	C++17	100 / 100	2264 ms	15904 KiB

bridges

#include <bits/stdc++.h>
using namespace std;
// #pragma GCC optimize("Ofast")
#define OPTM ios_base::sync_with_stdio(0); cin.tie(0);
#define INF int(1e9+7)
#define ln '\n' 
#define ll long long
#define ull unsigned long long
#define ui unsigned int
#define us unsigned short
#define FOR(i,s,n) for (int i = s; i < n; i++)
#define FORR(i,n,s) for (int i = n; i > s; i--)
#define FORX(u, arr) for (auto u : arr)
#define PB push_back
#define in(v,x) (v.find(x) != v.end())
#define F first
#define S second
#define PII pair<int, int>
#define PLL pair<ll, ll>
#define UM unordered_map
#define US unordered_set
#define PQ priority_queue
#define ALL(v) v.begin(), v.end()
const ll LLINF = 1e18+1;

struct Query {
    int idx,x,y;
};

const int MAXN = 1e5+1, BLOCK = 425;
int n,m,q;
int p[MAXN], sz[MAXN], res[MAXN];
vector<pair<PII,PII>> e;
vector<Query> qu1, qu2;
int ans, mp[MAXN];
set<PII> h;
vector<PII> edges;
int wt[MAXN];
vector<int> v[MAXN];
int val[MAXN];
bool z[MAXN], z1[MAXN], z2[MAXN], z3[MAXN];
bool prnt[MAXN];

int finds(int a) {
  if (p[a] != a) p[a] = finds(p[a]);
  return p[a];
}

void unite(int a, int b) {
  a = finds(a);
  b = finds(b);
  if (a != b) {
    if (sz[a] < sz[b]) swap(a,b);
    p[b] = a;
    sz[a] += sz[b];
  }
}

void dfs(int s) {
    if (z[s]) return;
    z[s] = 1;
    ans += sz[s];
    FORX(u,v[s]) {
        dfs(u);
    }
}

bool cmp(const Query& a, const Query& b) {
    return a.y > b.y;
}

signed main() {
    OPTM;
    cin >> n >> m;
    FOR(i,0,m) {
        int a,b,w; cin >> a >> b >> w;
        e.PB({{w,i},{a,b}});
        h.insert({-w,i});
        edges.PB({a,b});
        wt[i] = w;
    }
    //sort(ALL(e),greater<pair<PII,PII>>());
    
    cin >> q;
    int i = 0;
    while (i < q) {
        int bruh = 0;
        FORX(u,h) {
            e[bruh] = {{-u.F,u.S},edges[u.S]};
            bruh++;
        }
        FOR(l,0,m) mp[e[l].F.S] = l;
        qu1.clear(); qu2.clear();
        FOR(l,1,n+1) {
            p[l] = l;
            sz[l] = 1;
        }
        int j = 0;
        vector<int> vis;
        while (j < BLOCK && i < q) {
            int t,s,w; cin >> t >> s >> w;
            if (t == 1) {
                qu1.PB({i,s-1,w});
                if (!z3[s-1]) {
                    z3[s-1] = 1;
                    vis.PB(s-1);
                }
            }
            else {
                qu2.PB({i,s,w});
                prnt[i] = 1;
            }
            j++; i++;
        }
        sort(ALL(qu2),cmp);
        vector<pair<int,PII>> e1;
        FOR(j,0,m) if (!z3[e[j].F.S]) e1.PB({e[j].F.F,e[j].S});
        int en = e1.size();
        int q1n = qu1.size(), q2n = qu2.size();
        int k = 0;
        FOR(j,0,q2n) {
            // cout << "--------------------------------------- " << j << ln;
            // cout << qu2[j].idx << " " << qu2[j].x << " " << qu2[j].y << ln;
            while (k < en && e1[k].F >= qu2[j].y) {
                unite(e1[k].S.F, e1[k].S.S);
                k++;
            }
            //ans = sz[finds(qu2[j].x)];
            ans = 0;
            // FOR(l,0,m) cout << val[l] << ' ';
            // cout << ln;
            FOR(l,0,q1n) {
                int pos = mp[qu1[l].x], w = qu1[l].y;
                if (qu1[l].idx < qu2[j].idx) val[pos] = w;
                else if (!val[pos]) val[pos] = e[pos].F.F;
            }
            vector<int> toclear;
            FOR(l,0,q1n) {
                int pos = mp[qu1[l].x];
                if (!z1[pos] && val[pos] >= qu2[j].y) {
                    int a = finds(e[pos].S.F), b = finds(e[pos].S.S);
                    z1[pos] = 1;
                    v[a].PB(b);
                    v[b].PB(a);
                    if (!z2[a]) {
                        z2[a] = 1;
                        toclear.PB(a);
                    }
                    if (!z2[b]) {
                        z2[b] = 1;
                        toclear.PB(b);
                    }
                }
            }
            // cout << "finds: " << finds(qu2[j].x) << ln;
            // FOR(l,1,n+1) cout << z[l] << ' ';
            // cout << ln;
            int start = finds(qu2[j].x);
            dfs(start);
            if (!z2[start]) {
                z2[start] = 1;
                toclear.PB(start);
            }
            // FOR(l,1,n+1) cout << sz[l] << ' ';
            // cout << ln;
            // cout << "ans: " << ans << ln;
            res[qu2[j].idx] = ans;
            // FOR(l,1,n+1) {
            //     cout << l << ": ";
            //     FORX(u,v[l]) cout << u << ' ';
            //     cout << ln;
            // }
            // cout << ln;
            FORX(u,toclear) {
                //cout << u << ' ';
                z[u] = z2[u] = 0;
                v[u].clear();
            }
            FORX(u,vis) z3[u] = 0;
            // cout << ln;
            FOR(l,0,q1n) val[mp[qu1[l].x]] = z1[mp[qu1[l].x]] = 0;
        }
        // FOR(i,1,n+1) cout << finds(i) << ' ';
        // cout << ln;
        FOR(l,0,q1n) {
            int pos = qu1[l].x;
            h.erase({-wt[pos],pos});
            wt[pos] = qu1[l].y;
            h.insert({-wt[pos],pos});
        }
    }
    FOR(i,0,q) if (prnt[i]) cout << res[i] << ln;
}

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