Submission #1309968

#	Time	Username	Problem	Language	Result	Execution time	Memory
1309968		edo	Tug of War (BOI15_tug)	C++20	100 / 100	898 ms	10356 KiB

tug

#include <bits/stdc++.h>

using namespace std;
using ll   = long long;
using vi   = vector<int>;
using vll  = vector<ll>;
using vvi  = vector<vi>;
using vvll = vector<vll>;
using pii  = pair<int,int>;
using pll  = pair<ll,ll>;
using ui    = unsigned int;
using ull   = unsigned long long;
using pui   = pair<ui,ui>;
using pull  = pair<ull,ull>;
using i128 = __int128_t;

template<typename T>
using vc = std::vector<T>;


#define YES cout << "YES\n"
#define NO  cout << "NO\n"
#define yes cout << "yes\n"
#define no  cout << "no\n"
#define Yes cout << "Yes\n"
#define No  cout << "No\n"

template<typename T> void sc(T &x) { cin >> x; }
template<typename T, typename U> void sc(pair<T,U> &p) { sc(p.first), sc(p.second); }
template<typename T> void sc(vector<T> &v) { for (auto &x : v) sc(x); }
template<typename... A> void sc(A&... a) { (sc(a), ...); }


template<typename T> void _pt(const T &x){cout << x;}
template<typename T, typename U> void _pt(const pair<T,U> &p){_pt(p.first); cout << ' '; _pt(p.second);}
template<typename T> void _pt(const vector<T> &v){bool f=1; for(auto &x:v){if(!f) cout<<' '; _pt(x); f=0;}}
template<typename... A> void pt(const A&... a){(_pt(a), ...);}


template<typename T, typename U> bool umin(T &a, const U &b) { return b < a ? (a = b, true) : false; }
template<typename T, typename U> bool umax(T &a, const U &b) { return b > a ? (a = b, true) : false; }
template<typename T> T maxel(const vector<T>& v){ return *max_element(v.begin(), v.end()); }
template<typename T> T minel(const vector<T>& v){ return *min_element(v.begin(), v.end()); }
template<typename T, int N> T maxel(T (&a)[N]) { return *max_element(a, a + N); }
template<typename T, int N> T minel(T (&a)[N]) { return *min_element(a, a + N); }


template<typename C, typename T> auto lb(C& c, const T& x){ return std::lower_bound(c.begin(), c.end(), x); }
template<typename C, typename T> auto ub(C& c, const T& x){ return std::upper_bound(c.begin(), c.end(), x); }

template<typename T> auto lb(std::set<T>& s, const T& x){ return s.lower_bound(x); }
template<typename T> auto ub(std::set<T>& s, const T& x){ return s.upper_bound(x); }
template<typename T> auto lb(const std::set<T>& s, const T& x){ return s.lower_bound(x); }
template<typename T> auto ub(const std::set<T>& s, const T& x){ return s.upper_bound(x); }

#define GET_MACRO(_1,_2,_3,_4,NAME,...) NAME
#define FOR1(n)            for (int i=0; i<(n); ++i)
#define FOR2(i,n)          for (int i=0; i<(n); ++i)
#define FOR3(i,l,r)        for (int i=(l); i<(r); ++i)
#define FOR4(i,l,r,k)      for (int i=(l); i<(r); i+=(k))
#define FOR(...)           GET_MACRO(__VA_ARGS__, FOR4, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define ROF1(n)            for (int i=(n)-1; i>=0; --i)
#define ROF2(i,n)          for (int i=(n)-1; i>=0; --i)
#define ROF3(i,l,r)        for (int i=(r)-1; i>=(l); --i)
#define ROF4(i,l,r,k)      for (int i=(r)-1; i>=(l); i-=(k))
#define ROF(...)           GET_MACRO(__VA_ARGS__, ROF4, ROF3, ROF2, ROF1)(__VA_ARGS__)
#define all(c)   (c).begin(), (c).end()
#define allr(c)  (c).rbegin(), (c).rend()
#define eb       emplace_back
#define mp       make_pair
#define mt       make_tuple
#define fi       first
#define se       second
#define pb       push_back
#define trav(x,a) for (auto &x : (a))
#define sz(a) ((int)(a).size())
#define mem(a,v) memset(a, v, sizeof(a))
#define nl pt("\n")


int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, k;
    sc(n, k);
    n <<= 1;
    vi l(n), r(n), s(n);
    set<int> g[n];

    FOR(n) {
        sc(l[i], r[i], s[i]); --l[i]; --r[i];
        r[i] += (n >> 1);
        g[l[i]].emplace(i);
        g[r[i]].emplace(i);
    }

    int p = n * 10;
    queue<int> q;
    int tren = 0;
    auto flag = [](int x) {
        !x ? YES : NO;
        exit(0);
    };
    FOR(n) {
        if(!sz(g[i]))
            flag(2);
        if(sz(g[i]) == 1)
            q.push(i);
    }

    while(!q.empty()) {
        int u = q.front(); q.pop();
        tren = *g[u].begin(); 
        int v = u ^ l[tren] ^ r[tren];
        g[v].erase(tren);
        p += u < n / 2 ? s[tren] : -s[tren];
        if(sz(g[v]) == 1) 
            q.push(v);
    }

    vi xs;
    FOR(n) {
        if(sz(g[i]) < 2)
            continue;
        int tmp = 0;
        int j = i;
        while(sz(g[j])) {
            tren = *g[j].begin();
            tmp += j < n / 2 ? s[tren] : -s[tren];
            g[l[tren]].erase(tren);
            g[r[tren]].erase(tren);
            j ^= l[tren] ^ r[tren];
        }
        if(tmp < 0) tmp *= -1;
        p -= tmp;
        xs.pb(tmp << 1);
    }

    bitset<20 * (int)6e4 + 1> dp;
    dp[p] = 1;
    trav(x, xs) {
        dp |= dp << x;
    }


    FOR(i, 10 * n - k, 10 * n + k + 1) {
        if(dp[i])
            flag(0);
    }

    flag(1);

    return 0;
}

• Subtask 1: 18 / 18
• Subtask 2: 30 / 30
• Subtask 3: 23 / 23
• Subtask 4: 29 / 29