Submission #629004

#	Time	Username	Problem	Language	Result	Execution time	Memory
629004		Joshua_Andersson	Tug of War (BOI15_tug)	C++14	100 / 100	44 ms	9620 KiB

tug

#undef _GLIBCXX_DEBUG                // disable run-time bound checking, etc
#pragma GCC optimize("Ofast,inline") // Ofast = O3,fast-math,allow-store-data-races,no-protect-parens
#pragma GCC optimize ("unroll-loops")

#pragma GCC target("bmi,bmi2,lzcnt,popcnt")                      // bit manipulation
#pragma GCC target("movbe")                                      // byte swap
#pragma GCC target("aes,pclmul,rdrnd")                           // encryption
#pragma GCC target("avx,avx2,f16c,fma,sse3,ssse3,sse4.1,sse4.2") // SIMD

#include <bits/stdc++.h>
using namespace std;

#define enablell 0

typedef long long ll;
const int mod = 1e9 + 7;
#if enablell
#define int ll
#define inf int(1e18)
#define float double
#else
const int inf = int(2e9);
#endif
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vvvi> vvvvi;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<vvb> vvvb;
typedef pair<int, int> p2;
typedef vector<p2> vp2;
typedef vector<vp2> vvp2;
typedef vector<vvp2> vvvp2;
typedef tuple<int, int, int> p3;
typedef vector<p3> vp3;
typedef vector<vp3> vvp3;
typedef vector<vvp3> vvvp3;
typedef tuple<int, int, int, int> p4;
typedef vector<p4> vp4;

#define _LOCAL _MSC_VER > 0
#if _LOCAL
#define gc() getchar()
#define popcount(x) __popcnt(x)
#define leading_zeros(x) _lzcnt_u32(x)
#define assert(x) debassert(x)
#else
#define popcount(x) __builtin__popcount(x)
#define leading_zeros(x) __builtin_clz(x)
#define gc() getchar_unlocked()
#if 0
#include <bits/extc++.h>
using namespace __gnu_pbds;
struct chash { // large odd number for C
    const uint64_t C = ll(4e18 * acos(0)) | 71;
    ll operator()(ll x) const { return x; }
};
//typedef __gnu_pbds::gp_hash_table<int, null_type, chash> h;
#endif

#endif

#if 1
inline void read(int& v) { v = 0; int sign = 1; char c = gc(); if (c == '-') { sign = -1; } else { v += c - '0'; } while ((c = gc()) != EOF && c != ' ' && c != '\n') { v *= 10; v += c - '0'; } v *= sign; }
inline void read(int& u, int& v) { read(u); read(v); }
//inline void read(int& v) { char c; while ((c = getchar()) != EOF && c != ' ' && c != '\n') { v *= 10; v += c - '0'; } }
inline void read(string& s) { char c; while ((c = gc()) != EOF && c != '\n' && c != ' ') { s.push_back(c); } }
#else
template <typename T> inline void read(T& a) { cin >> a; }
template <typename T> inline void read(T& a, T& b) { cin >> a >> b; }
template <typename T> inline void read(T& a, T& b, T& c) { cin >> a >> b >> c; }
#endif
template <typename T> inline void write(T& a) { cout << (a) << "\n"; }
#define quit cout << endl; _Exit(0);
#define dread(type, a) type a; read(a)
#define dread2(type, a, b) dread(type, a); dread(type, b)
#define dread3(type, a, b, c) dread2(type, a, b); dread(type, c)
#define dread4(type, a, b, c, d) dread3(type, a, b, c); dread(type, d)
#define dread5(type, a, b, c, d, e) dread4(type, a, b, c, d); dread(type, e)
#define readvector(type, name, size) vector<type> name(size); rep(i,size) {dread(type,temp); name[i]=temp;}
#ifdef _DEBUG
#define noop cout << "";
#define deb __debugbreak();
#define debassert(expr) if (!(expr)) deb;
#define debif(expr) if(expr) deb;
#else
#define noop ;
#define deb ;
#define debassert(expr) ;
#define debif(expr) ;
#endif

#define rep(i, high) for (int i = 0; i < high; i++)
#define repp(i, low, high) for (int i = low; i < high; i++)
#define repe(i, container) for (auto& i : container)
#define per(i, high) for (int i = high-1; i >= 0; i--)
#define perr(i, low, high) for (int i = high-1; i >= low; i--)

#define all(a) a.begin(),a.end()
#define revall(a) a.rbegin(),a.rend()
#define setcontains(set, x) (set.find(x) != set.end())
#define within(a, b, c, d) (a >= 0 && a < b && c >= 0 && c < d)
#define sz(container) ((int)container.size())
#define mp(a,b) (make_pair(a,b))
#define first(a) (*begin(a))
#define indexpair(p, i) ((i==0)?p.first:p.second)
#define chmax(a,b) ((a)=max((a),b))
#define chmin(a,b) ((a)=min((a),b))

#define ceildiv(x,y) ((x + y - 1) / y)
#define fract(a) (a-floor(a))

#if 1
auto Start = chrono::high_resolution_clock::now();
#define elapsedmillis() (chrono::duration_cast<chrono::milliseconds>(chrono::high_resolution_clock::now() - Start).count())
#define rununtil(time) if (elapsedmillis() >= time) break;
random_device rd;
mt19937 rng(rd());
#endif

inline void fast() { ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); }
template <typename T, typename U> inline void operator+=(pair<T, U>& l, const pair<T, U>& r) { l = { l.first + r.first,l.second + r.second }; }
template <typename T, typename U> inline pair<T, U> operator+(const pair<T, U> l, const pair<T, U> r) { return { l.first + r.first, l.second + r.second }; }
template <typename T, typename U> inline pair<T, U> operator-(const pair<T, U> l, const pair<T, U> r) { return { l.first - r.first, l.second - r.second }; }
template <typename T, typename U> inline pair<T, U> operator*(const pair<T, U> l, const int m) { return { l.first * m, l.second * m }; }
template <typename Out> inline void split(const string& s, char delim, Out result) { istringstream iss(s); string item; while (getline(iss, item, delim)) { *result++ = item; } }
inline vector<string> split(const string& s, char delim) { vector<string> elems; split(s, delim, back_inserter(elems)); return elems; }

void die()
{
    cout << "NO";
    quit;
}

#define vset vector<multiset<p2>>

p2 dfs(int u, int p, int d, vi& visited, vset& edges)
{
    if (visited[u]) return mp(0, 0);
    visited[u] = true;
    repe(edge, edges[u])
    {
        if (edge.first == p) continue;
        return mp(edge.second*((d+1)%2), edge.second * (d % 2)) + dfs(edge.first, u, d + 1, visited, edges);
    }
}

int32_t main()
{
    fast();

#if 0
    //ifstream cin("C:\\Users\\Matis\\source\\repos\\Comp prog\\x64\\Debug\\in.txt");
    //ifstream cin("C:\\Users\\Matis\\desktop\\po-two\\swedish-olympiad-2014\\");
#endif

    dread2(int, n, k);

    vector<multiset<p2>> edges(n*2);

    rep(i, 2*n)
    {
        dread3(int, a, b, w);
        a--; b--; b += n;
        edges[a].insert(mp(b, w));
        edges[b].insert(mp(a, w));
    }

    int sum = 0;

    rep(i, 2 * n) if (edges[i].empty()) die();

    // Find all leaves
    vb mated(2 * n);
    queue<int> leaves;
    rep(i, 2 * n) if (edges[i].size() == 1) leaves.push(i);

    while (leaves.size())
    {
        int l = leaves.front();
        leaves.pop();

        if (edges[l].empty() && !mated[l]) die();
        int parent = edges[l].begin()->first;

        mated[l] = true;
        edges[parent].erase(mp(l, edges[l].begin()->second));
        if (edges[parent].size()==1)
        {
            leaves.push(parent);
        }

        if (l < n) sum += edges[l].begin()->second;
        else sum -= edges[l].begin()->second;
        edges[l] = multiset<p2>();
    }

    rep(i, 2 * n) if (!mated[i] && edges[i].size() == 0) die();


    // Hopefully deg(v)=2 for all v now
    // Graph should now be components of cycles of even length

    //rep(i, 2 * n) assert(edges[i].size() % 2 == 0);

    vp2 cyclelens;
    vi visited(2 * n);

    rep(i, 2 * n)
    {
        if (visited[i]||edges[i].empty()) continue;
        // Cycle of len 2
        if (edges[i].begin()->first == next(edges[i].begin())->first)
        {
            cyclelens.emplace_back(edges[i].begin()->second, next(edges[i].begin())->second);
            visited[i] = true;
            visited[edges[i].begin()->first] = true;
        }
        else
        {
            cyclelens.emplace_back(dfs(i, -1, 0, visited, edges));

        }
    }

    bitset<30001*20> dp;
    dp[0] = 1;

    int s = 0;

    map<int,int> diffs;
    rep(i, cyclelens.size()) diffs[abs(cyclelens[i].first - cyclelens[i].second)]++;

    repe(diff,diffs)
    {
        
        

        s += diff.first*diff.second;

        vi items;
        int k = 1;
        while (diff.second > k)
        {
            items.push_back(k);
            diff.second -= k;
            k *= 2;
        }
        if (diff.second != 0) items.push_back(diff.second);

        repe(item, items) dp |= dp << (2*diff.first*item);
    }

    repp(i, s, dp.size())
    {
        if (dp[i]&&abs(i-s+sum)<=k)
        {
            cout << "YES";
            quit;
        }
    }

    die();

    quit;
}

Compilation message (stderr)

tug.cpp: In function 'int32_t main()':
tug.cpp:94:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   94 | #define rep(i, high) for (int i = 0; i < high; i++)
......
  233 |     rep(i, cyclelens.size()) diffs[abs(cyclelens[i].first - cyclelens[i].second)]++;
      |         ~~~~~~~~~~~~~~~~~~~             
tug.cpp:233:5: note: in expansion of macro 'rep'
  233 |     rep(i, cyclelens.size()) diffs[abs(cyclelens[i].first - cyclelens[i].second)]++;
      |     ^~~
tug.cpp:95:48: warning: comparison of integer expressions of different signedness: 'int' and 'std::size_t' {aka 'long unsigned int'} [-Wsign-compare]
   95 | #define repp(i, low, high) for (int i = low; i < high; i++)
......
  255 |     repp(i, s, dp.size())
      |          ~~~~~~~~~~~~~~~                        
tug.cpp:255:5: note: in expansion of macro 'repp'
  255 |     repp(i, s, dp.size())
      |     ^~~~
tug.cpp: In function 'p2 dfs(int, int, int, vi&, std::vector<std::multiset<std::pair<int, int> > >&)':
tug.cpp:147:1: warning: control reaches end of non-void function [-Wreturn-type]
  147 | }
      | ^

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