Submission #660226

#	Time	Username	Problem	Language	Result	Execution time	Memory
660226		bojackduy	Bridges (APIO19_bridges)	C++14	100 / 100	2007 ms	42752 KiB

bridges

#include <iostream>
#include <queue>
#include <stack>
#include <algorithm>
#include <string.h>
#include <functional>
#define task ""
#define size() size() * 1ll 
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define pii pair<int, int>
#define fi first
#define se second
#define MASK(x) (1LL << (x))
#define BIT(x,i) (((x) >> (i)) & 1)
#define numbit(x) __builtin_popcountll(x)

using namespace std;

typedef vector<int> vi;
typedef vector<pii> vii;
typedef long long ll;

template<class t>
bool mini(t &x,t y) {
    if (y < x) {
       x = y;
       return 1;
    }
return 0;
}
template<class t>
bool maxi(t &x,t y) {
    if (x < y) {
       x = y;
       return 1;
    }
return 0;
}

const int N = 1e6 + 1;
const int M = 1e3 + 1;
const long long mod = 1e9 + 7;
const long long oo = 1e18 + 7;

int n, m, q;
int u[N], v[N], w[N], t[N], id[N], z[N], lab[N], ans[N];
vi b[N];
bool changed[N];
stack<array<int, 3>> st;
int root(int u) {
    return (lab[u] < 0 ? u : root(lab[u]));
}
bool join(int u, int v) {
    if ((u = root(u)) == (v = root(v))) return 0;
    if (lab[u] > lab[v]) swap(u, v);
    st.push({u, v, lab[v]});
    lab[u] += lab[v];
    lab[v] = u;
return 1;
}
void roll_back(int sz) {
    while (st.size() > sz) {
        int u = st.top()[0];
        int v = st.top()[1];
        int w = st.top()[2];
        st.pop();
        lab[u] -= w;
        lab[v] = w;
    }
}
void solve(int test = -1) {
    memset(lab, -1, sizeof lab);
    memset(ans, -1, sizeof ans);
    cin >> n >> m;
    for (int i = 1; i <= m; i++) {
        cin >> u[i] >> v[i] >> w[i];
    }
    cin >> q;
    for (int i = 1; i <= q; i++) {
        cin >> t[i] >> id[i] >> z[i];
    }
    int blsz = 1000;
    for (int l = 1; l <= q; l += blsz) {
        int r = min(q, l + blsz - 1);
        
        vi calc, upd, unchanged;
        for (int i = l; i <= r; i++) {
            if (t[i] == 1) {
                changed[id[i]] = 1;
                upd.pb(i);
            } else {
                calc.pb(i);
            }
        }
        for (int i = 1; i <= m; i++) if (!changed[i]) unchanged.pb(i);
        sort(all(unchanged), [&](const int &x, const int &y) {
            return w[x] > w[y];
        });
        sort(all(calc), [&](const int &x, const int &y) {
            return z[x] > z[y];
        });
        for (int i = l; i <= r; i++) {
            if (t[i] == 1) {
                w[id[i]] = z[i];
                changed[id[i]] = 0;
            } else {
                b[i - l].clear();
                for (int x: upd) if (w[id[x]] >= z[i]) b[i - l].pb(x);
            }
        }
        for (int j = 0, i = 0; i < calc.size(); i++) {
            while (j < unchanged.size() && w[unchanged[j]] >= z[calc[i]]) {
                join(u[unchanged[j]], v[unchanged[j]]);
                j++;
            }
            int sz = st.size();
            for (int x: b[calc[i] - l]) {
                join(u[id[x]], v[id[x]]);
            }
            ans[calc[i]] = -lab[root(id[calc[i]])];
            roll_back(sz);
        }
        roll_back(0);
    }
    for (int i = 1; i <= q; i++) if (ans[i] != -1) cout << ans[i] << '\n';
}

int32_t main()  {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    // freopen(task".inp", "r", stdin);
    // freopen(task".out", "w", stdout);

    int T = 1;
    // cin >> T;
    for (int i = 1; i <= T; i++) {
        solve(i);
    }
return 0;
}
/*

*/

Compilation message (stderr)

bridges.cpp: In function 'void roll_back(int)':
bridges.cpp:63:22: warning: comparison of integer expressions of different signedness: 'long long unsigned int' and 'int' [-Wsign-compare]
   63 |     while (st.size() > sz) {
      |            ~~~~~~~~~~^~~~
bridges.cpp: In function 'void solve(int)':
bridges.cpp:112:34: warning: comparison of integer expressions of different signedness: 'int' and 'long long unsigned int' [-Wsign-compare]
  112 |         for (int j = 0, i = 0; i < calc.size(); i++) {
      |                                  ^
bridges.cpp:113:22: warning: comparison of integer expressions of different signedness: 'int' and 'long long unsigned int' [-Wsign-compare]
  113 |             while (j < unchanged.size() && w[unchanged[j]] >= z[calc[i]]) {
      |                      ^

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