Submission #1105189

#	Time	Username	Problem	Language	Result	Execution time	Memory
1105189		tradz	Dynamic Diameter (CEOI19_diameter)	C++14	24 / 100	1313 ms	32124 KiB

diameter

#include <bits/stdc++.h>
#define TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define For(i,a,b) for(int i = a; i <= b; i++)
#define Ford(i,a,b) for(int i = a; i >= b; i--)
#define ll long long
#define ii pair<int,int>
#define fi first
#define se second
#define all(v) v.begin(),v.end()
#define RRH(v) v.resize(unique(all(v)) - v.begin())

using namespace std;
const int  N = 1e6+7;
const int M = 1e9+7;
const ll oo = 3e18;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

long long GetRandom(long long l, long long r) {
    return uniform_int_distribution<long long> (l, r)(rng);
}

int n, q;
ll w;
pair <int, int> e[N];
vector<pair<int, ll>> g[N];

namespace sub1 {
    ll last = 0, c, len[N];
    int d;
    void dfs(int u, int pre, int su, int sv) {
        for (int i = 0; i < g[u].size(); i++) {
            int v;
            ll w;
            tie(v, w) = g[u][i];
            if (v == pre) {
                if ((u == su) && (v == sv)) {
                    g[u][i].se = c;
                }
                else if ((v == su) && (u == sv)) {
                    g[u][i].se = c;
                }
                continue;
            }
            if ((u == su) && (v == sv)) {
                g[u][i].se = c;
            }
            else if ((u == sv) && (v == su)) {
                g[u][i].se = c;
            }
            w = g[u][i].se;
            len[v] = len[u] + w;
            dfs(v, u, su, sv);
        }
    }

    void solve() {
        for (int i = 1; i <= n; i++) len[i] = 0;
        len[0] = 0;
        while (q--) {
            cin >> d >> c;
            d = (1ll * d + last) % (n - 1);
            c = (c + last) % w;
            dfs(1, 0, e[d].fi, e[d].se);
            int mx = 0;
            for (int i = 1; i <= n; i++) {
                if (len[mx] < len[i]) {
                    mx = i;
                }
            }
            len[mx] = 0;
            dfs(mx, 0, e[d].fi, e[d].se);
            mx = 0;
            for (int i = 1; i <= n; i++) {
                if (len[mx] < len[i]) {
                    mx = i;
                }
            }
        //    cout << d << " " << c << '\n';
            if (q > 0) cout << len[mx] << '\n';
            else cout << len[mx];
            last = len[mx];
        }
    }
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0);

    #define TASK ""
    if (fopen (".inp", "r")) {
        freopen (".inp", "r", stdin);
        freopen (".out", "w", stdout);
    }
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }


    cin >> n >> q >> w;
    For (i, 0, n - 2) {
        int u, v;
        ll c;
        cin >> u >> v >> c;
        e[i] = {u, v};
        g[u].push_back({v, c});
        g[v].push_back({u, c});
    }

    if (max(n, q) <= 5000) {
        sub1 :: solve();
        return 0;
    }


    cerr << "Time elapsed: " << TIME << " s.\n";
    return 0;
}

Compilation message (stderr)

diameter.cpp: In function 'void sub1::dfs(int, int, int, int)':
diameter.cpp:32:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         for (int i = 0; i < g[u].size(); i++) {
      |                         ~~^~~~~~~~~~~~~
diameter.cpp: In function 'int main()':
diameter.cpp:92:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |         freopen (".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~
diameter.cpp:93:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |         freopen (".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
diameter.cpp:96:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
diameter.cpp:97:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   97 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 0 / 7
• Subtask 4: 0 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 27