Submission #43133

#	Time	Username	Problem	Language	Result	Execution time	Memory
43133		aquablitz11	Race (IOI11_race)	C++14	21 / 100	3060 ms	13112 KiB

race

// headers
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
// types
template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
using dbl = double;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template<class T> using MaxHeap = priority_queue<T>;
template<class T> using MinHeap = priority_queue<T, vector<T>, greater<T>>;
// loops
#define forx(i, x, y) for (int i = (x); i <= (y); ++i)
#define forn(i, n) for (int i = 0; i < (n); ++i)
#define for1(i, n) for (int i = 1; i <= (n); ++i)
#define rofx(i, x, y) for (int i = x; i >= y; --i)
#define rofn(i, n) for (int i = n-1; i >= 0; --i)
#define rof1(i, n) for (int i = n; i >= 1; --i)
#define fora(x, v) for (auto x : v)
// define shortcuts
#define all(x) begin(x), end(x)
#define pb push_back
#define eb emplace_back
#define F first
#define S second
#define X first
#define Y second
#define MP make_pair
#define MT make_tuple
// functions
template<class T> inline bool hasbit(T x, int i) { return x&(1<<i); }
template<class T> inline T togbit(T x, int i) { return x|(1<<i); }
template<class T> inline T setbit(T x, int i) { return x|(1<<i); }
template<class T> inline T rembit(T x, int i) { return x&~(1<<i); }
template<class T> inline bool setmax(T &a, const T &b) { return b > a ? a = b, true : false; }
template<class T> inline bool setmin(T &a, const T &b) { return b < a ? a = b, true : false; }
template<class T> int compress(vector<T> &v) { sort(all(v)); v.resize(unique(all(v))-v.begin()); return v.size(); }
// read functions
int read_int() { int x; scanf("%d", &x); return x; }
ll read_ll() { ll x; scanf("%" SCNd64, &x); return x; }
ull read_ull() { ull x; scanf("%" SCNu64, &x); return x; }
int read_dbl() { dbl x; scanf("%lf", &x); return x; }
void _R(int &x) { x = read_int(); }
void _R(ll &x) { x = read_ll(); }
void _R(dbl &x) { x = read_dbl(); }
void R() {}
template<class T, class... U> void R(T &head, U &... tail) { _R(head); R(tail...); }
// print functions
template<class T> void _W(const T &x) { cout << x; }
void _W(const int &x) { printf("%d", x); }
void _W(const ll &x) { printf("%" PRId64, x); }
void _W(const ull &x) { printf("%" PRIu64, x); }
void _W(const double &x) { printf("%.16f", x); }
void _W(const char &x) { putchar(x); }
void _W(const char *x) { printf("%s", x); }
template<class T> void _W(const vector<T> &x) { for (auto i = x.begin(); i != x.end(); _W(*i++)) if (i != x.cbegin()) putchar(' '); }
void W() {}
template<class T, class... U> void W(const T &head, const U &... tail) { _W(head); putchar(sizeof...(tail) ? ' ' : '\n'); W(tail...); }
// pseudo-random number generator
template<class T, T x1, T x2, T x3, int y1, int y2, int y3>
struct PRNG {
    using S = typename make_signed<T>::type;
    T s;
    PRNG(T _s = 0) : s(_s) {}
    T next() {
        T z = (s += x1);
        z = (z ^ (z >> y1)) * x2;
        z = (z ^ (z >> y2)) * x3;
        return z ^ (z >> y3);
    }
    T next(T n) { return next() % n; }
    S next(S l, S r) { return l + next(r - l + 1); }
    T operator()() { return next(); }
    T operator()(T n) { return next(n); }
    S operator()(S l, S r) { return next(l, r); }
    static T gen(T s) { return PRNG(s)(); }
    template<class U>
    void shuffle(U first, U last) {
        size_t n = last - first;
        for (size_t i = 0; i < n; i++) swap(first[i], first[next(i + 1)]);
    }
};
PRNG<uint32_t, 0x9E3779B1, 0x85EBCA6B, 0xC2B2AE35, 16, 13, 16> r32;
PRNG<uint64_t, 0x9E3779B97F4A7C15, 0xBF58476D1CE4E5B9, 0x94D049BB133111EB, 30, 27, 31> r64;
// program
int _main();
/*int main() {
    //ios::sync_with_stdio(false), cin.tie(0);
    //time_t begin = clock();
    int ret = _main();
    //time_t end = clock();
    //fprintf(stderr, "Program took %.3f seconds to compute\n", ((double)end-begin)/CLOCKS_PER_SEC);
    return ret;
}*/

/************************************************************
                CODE STARTS BELOW THIS POINT
************************************************************/

const int INF = 1e9;
const int N = 2e5+10;
const int K = 1e6+10;

int n, k;
vector<pii> G[N];
bool chk[N];

int sz[N];
void dfs(int u, int p) {
    sz[u] = 1;
    fora(v, G[u]) if (v.F != p && !chk[v.F])
        dfs(v.F, u), sz[u] += sz[v.F];
}

int cen, mns = INF;
void centroid(int u, int p, int s) {
    int z = sz[s]-sz[u];
    fora(v, G[u]) if (v.F != p && !chk[v.F]) {
        centroid(v.F, u, s);
        setmax(z, sz[v.F]);
    }
    if (z < mns) mns = z, cen = u;
}

int ans = INF;
int path[K], tst[K], tick;
void dfs1(int u, int p, int d, int l, bool fill) {
    if (d > k) return;
    if (!fill) {
        if (tst[k-d] == tick) setmin(ans, path[k-d]+l);
        if (d == k) setmin(ans, l);
    } else {
        if (tst[d] != tick) tst[d] = tick, path[d] = l;
        else setmin(path[d], l);
    }
    fora(v, G[u]) if (v.F != p && !chk[v.F]) dfs1(v.F, u, d+v.S, l+1, fill);
}

void process(int u) {
    ++tick;
    dfs(u, -1);
    mns = INF;
    centroid(u, -1, u);
    fora(v, G[u]) if (!chk[v.F]) dfs1(v.F, u, v.S, 1, 0), dfs1(v.F, u, v.S, 1, 1);
    chk[u] = true;
    fora(v, G[u]) if (!chk[v.F]) process(v.F);
}

int best_path(int _N, int _K, int H[][2], int L[]) {
    n = _N, k = _K;
    forn(i, n-1) {
        int u = H[i][0], v = H[i][1], w = L[i];
        G[u].eb(v, w);
        G[v].eb(u, w);
    }
    process(0);
    if (ans == INF)
        ans = -1;
    return ans;
}

int h[N][2], l[N];
int _main()
{
    int n, k;
    R(n, k);
    forn(i, n-1)
        R(h[i][0], h[i][1], l[i]);
    W(best_path(n, k, h, l));
    
    return 0;
}

Compilation message (stderr)

race.cpp: In function 'll read_ll()':
race.cpp:46:42: warning: format '%ld' expects argument of type 'long int*', but argument 2 has type 'll* {aka long long int*}' [-Wformat=]
 ll read_ll() { ll x; scanf("%" SCNd64, &x); return x; }
                                        ~~^
race.cpp: In function 'ull read_ull()':
race.cpp:47:45: warning: format '%lu' expects argument of type 'long unsigned int*', but argument 2 has type 'ull* {aka long long unsigned int*}' [-Wformat=]
 ull read_ull() { ull x; scanf("%" SCNu64, &x); return x; }
                                           ~~^
race.cpp: In function 'void _W(const ll&)':
race.cpp:57:44: warning: format '%ld' expects argument of type 'long int', but argument 2 has type 'll {aka long long int}' [-Wformat=]
 void _W(const ll &x) { printf("%" PRId64, x); }
                                           ~^
race.cpp: In function 'void _W(const ull&)':
race.cpp:58:45: warning: format '%lu' expects argument of type 'long unsigned int', but argument 2 has type 'ull {aka long long unsigned int}' [-Wformat=]
 void _W(const ull &x) { printf("%" PRIu64, x); }
                                            ~^
race.cpp: In function 'int read_int()':
race.cpp:45:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 int read_int() { int x; scanf("%d", &x); return x; }
                         ~~~~~^~~~~~~~~~
race.cpp: In function 'll read_ll()':
race.cpp:46:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 ll read_ll() { ll x; scanf("%" SCNd64, &x); return x; }
                      ~~~~~^~~~~~~~~~~~~~~~
race.cpp: In function 'ull read_ull()':
race.cpp:47:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 ull read_ull() { ull x; scanf("%" SCNu64, &x); return x; }
                         ~~~~~^~~~~~~~~~~~~~~~
race.cpp: In function 'int read_dbl()':
race.cpp:48:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 int read_dbl() { dbl x; scanf("%lf", &x); return x; }
                         ~~~~~^~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57