Submission #537519

#	Time	Username	Problem	Language	Result	Execution time	Memory
537519		maomao90	Paths (RMI21_paths)	C++17	12 / 100	107 ms	10184 KiB

Main

// Hallelujah, praise the one who set me free
// Hallelujah, death has lost its grip on me
// You have broken every chain, There's salvation in your name
// Jesus Christ, my living hope
#include <bits/stdc++.h> 
using namespace std;

template <class T>
inline bool mnto(T& a, T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T& a, T b) {return a < b ? a = b, 1: 0;}
#define REP(i, s, e) for (int i = s; i < e; i++)
#define RREP(i, s, e) for (int i = s; i >= e; i--)
typedef long long ll;
typedef long double ld;
#define MP make_pair
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, int> pll;
#define MT make_tuple
typedef tuple<int, int, int> iii;
#define ALL(_a) _a.begin(), _a.end()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

#define INF 1000000005
#define LINF 1000000000000000005ll
#define MAXN 100005

int n, k;
vii adj[MAXN];

multiset<ll> st;
ll mx[MAXN];
void dfs(int u, int p) {
    mx[u] = 0;
    bool leaf = 1;
    for (auto [v, w] : adj[u]) {
        if (v == p) continue;
        leaf = 0;
        dfs(v, u);
        auto it = st.find(mx[v]);
        st.insert(mx[v] + w);
        if (it != st.end()) {
            st.erase(st.find(mx[v]));
        } else {
            st.erase(st.begin());
        }
        mxto(mx[u], mx[v] + w);
    }
    if (leaf && st.size() < k) {
        st.insert(0);
    }
}

ll cur, ans[MAXN];
void reroot(int u, int p) {
    pll fmx = MP(0, u), smx = MP(0, u);
    for (auto [v, w] : adj[u]) {
        if (mx[v] + w >= fmx.FI) {
            smx = fmx;
            fmx = MP(mx[v] + w, v);
        } else if (mx[v] + w > smx.FI) {
            smx = MP(mx[v] + w, v);
        }
    }
    ans[u] = cur;
    for (auto [v, w] : adj[u]) {
        if (v == p) continue;
        auto it = st.find(mx[v] + w);
        st.insert(mx[v]);
        cur += mx[v];
        ll er2 = -1;
        if (it != st.end()) {
            er2 = mx[v] + w;
            st.erase(it);
            cur -= mx[v] + w;
        } else {
            er2 = *st.begin();
            cur -= *st.begin();
            st.erase(st.begin());
        }
        ll omx = mx[u];
        int o = -1;
        if (v == fmx.SE) {
            mx[u] = smx.FI;
            o = smx.SE;
        } else {
            mx[u] = fmx.FI;
            o = fmx.SE;
        }
        it = st.find(mx[u]);
        st.insert(mx[u] + w);
        cur += mx[u] + w;
        ll er1 = -1;
        if (it != st.end()) {
            er1 = mx[u];
            st.erase(it);
            cur -= mx[u];
        } else {
            er1 = *st.begin();
            cur -= *st.begin();
            st.erase(st.begin());
        }
        reroot(v, u);
        st.insert(er1);
        cur += er1;
        st.erase(mx[u] + w);
        cur -= mx[u] + w;
        mx[u] = omx;
        st.insert(er2);
        cur += er2;
        st.erase(mx[v]);
        cur -= mx[v];
    }
}

int main() {
#ifndef DEBUG
    ios::sync_with_stdio(0), cin.tie(0);
#endif
    cin >> n >> k;
    REP (i, 1, n) {
        int a, b, c; cin >> a >> b >> c;
        adj[a].pb(MP(b, c));
        adj[b].pb(MP(a, c));
    }
    if (k == 1) {
        vll dist(n + 1, 0);
        vll ans(n + 1, 0);
        auto dfs = [&] (auto &&self, int u, int p) {
            if (0) return -1;
            int mx = u;
            for (auto [v, w] : adj[u]) {
                if (v == p) continue;
                dist[v] = dist[u] + w;
                int x = self(self, v, u);
                if (dist[mx] < dist[x]) {
                    mx = x;
                }
            }
            return mx;
        };
        dist[1] = 0;
        int a = dfs(dfs, 1, -1);
        dist[a] = 0;
        int b = dfs(dfs, a, -1);
        REP (i, 1, n + 1) {
            mxto(ans[i], dist[i]);
        }
        dist[b] = 0;
        dfs(dfs, b, -1);
        REP (i, 1, n + 1) {
            mxto(ans[i], dist[i]);
        }
        REP (i, 1, n + 1) {
            cout << ans[i] << '\n';
        }
        return 0;
    }
    st.clear();
    dfs(1, -1);
    cur = 0;
    for (ll x : st) {
        cur += x;
    }
    ans[1] = cur;
    reroot(1, -1);
    REP (i, 1, n + 1) {
        cout << ans[i] << '\n';
    }
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void dfs(int, int)':
Main.cpp:58:27: warning: comparison of integer expressions of different signedness: 'std::multiset<long long int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   58 |     if (leaf && st.size() < k) {
      |                 ~~~~~~~~~~^~~
Main.cpp: In function 'void reroot(int, int)':
Main.cpp:91:13: warning: variable 'o' set but not used [-Wunused-but-set-variable]
   91 |         int o = -1;
      |             ^

• Subtask 1: 0 / 8
• Subtask 2: 0 / 11
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 12 / 12
• Subtask 6: 0 / 32