Submission #319022

#	Time	Username	Problem	Language	Result	Execution time	Memory
319022		jc713	Training (IOI07_training)	C++17	100 / 100	23 ms	8576 KiB

training

#include <bits/stdc++.h>
using namespace std;
 
using ll = long long;
using ld = long double;
using db = double; 
using str = string; // yay python!

using pi = pair<int,int>;
using pl = pair<ll,ll>;
using pd = pair<db,db>;

using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<db>; 
using vs = vector<str>;
using vpi = vector<pi>;
using vpl = vector<pl>; 
using vpd = vector<pd>;

#define tcT template<class T
// ^ lol this makes everything look weird but I'll try it
tcT> using V = vector<T>; 
tcT, size_t SZ> using AR = array<T,SZ>; 

// pairs
#define mp make_pair
#define f first
#define s second

// vectors
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define sor(x) sort(all(x)) 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

// loops
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5;
const ll INF = 1e18; // not too close to LLONG_MAX
const int IINF = 1e9;
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; // for every grid problem!!
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

// helper funcs
constexpr int pct(int x) { return __builtin_popcount(x); } // # of bits set
constexpr int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
ll cdiv(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded up
ll fdiv(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded down

tcT> bool ckmin(T& a, const T& b) {
	return b < a ? a = b, 1 : 0; } // set a = min(a,b)
tcT> bool ckmax(T& a, const T& b) {
	return a < b ? a = b, 1 : 0; }

#define tcTU tcT, class U
tcTU> T fstTrue(T lo, T hi, U f) {
	hi ++; assert(lo <= hi); // assuming f is increasing
	while (lo < hi) { // find first index such that f is true 
		T mid = lo+(hi-lo)/2;
		f(mid) ? hi = mid : lo = mid+1; 
	} 
	return lo;
}
tcTU> T lstTrue(T lo, T hi, U f) {
	lo --; assert(lo <= hi); // assuming f is decreasing
	while (lo < hi) { // find first index such that f is true 
		T mid = lo+(hi-lo+1)/2;
		f(mid) ? lo = mid : hi = mid-1;
	} 
	return lo;
}
tcT> void remDup(vector<T>& v) { // sort and remove duplicates
	sort(all(v)); v.erase(unique(all(v)),end(v)); }
tcTU> void erase(T& t, const U& u) { // don't erase
	auto it = t.find(u); assert(it != end(t));
	t.erase(u); } // element that doesn't exist from (multi)set

// INPUT
#define tcTUU tcT, class ...U
tcT> void re(complex<T>& c);
tcTU> void re(pair<T,U>& p);
tcT> void re(vector<T>& v);
tcT, size_t SZ> void re(AR<T,SZ>& a);

tcT> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
tcTUU> void re(T& t, U&... u) { re(t); re(u...); }

tcT> void re(complex<T>& c) { T a,b; re(a,b); c = {a,b}; }
tcTU> void re(pair<T,U>& p) { re(p.f,p.s); }
tcT> void re(vector<T>& x) { trav(a,x) re(a); }
tcT, size_t SZ> void re(AR<T,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
str ts(bool b) { 
	#ifdef LOCAL
		return b ? "true" : "false"; 
	#else 
		return ts((int)b);
	#endif
}
tcT> str ts(complex<T> c) { 
	stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) {
	str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
	res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
	str res = ""; F0R(i,SZ) res += char('0'+b[i]);
	return res; }
tcTU> str ts(pair<T,U> p);
tcT> str ts(T v) { // containers with begin(), end()
	#ifdef LOCAL
		bool fst = 1; str res = "{";
		for (const auto& x: v) {
			if (!fst) res += ", ";
			fst = 0; res += ts(x);
		}
		res += "}"; return res;
	#else
		bool fst = 1; str res = "";
		for (const auto& x: v) {
			if (!fst) res += " ";
			fst = 0; res += ts(x);
		}
		return res;

	#endif
}
tcTU> str ts(pair<T,U> p) {
	#ifdef LOCAL
		return "("+ts(p.f)+", "+ts(p.s)+")"; 
	#else
		return ts(p.f)+" "+ts(p.s);
	#endif
}

// OUTPUT
tcT> void pr(T x) { cout << ts(x); }
tcTUU> void pr(const T& t, const U&... u) { 
	pr(t); pr(u...); }
void ps() { pr("\n"); } // print w/ spaces
tcTUU> void ps(const T& t, const U&... u) { 
	pr(t); if (sizeof...(u)) pr(" "); ps(u...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
tcTUU> void DBG(const T& t, const U&... u) {
	cerr << ts(t); if (sizeof...(u)) cerr << ", ";
	DBG(u...); }
#ifdef LOCAL // compile with -DLOCAL, chk -> fake assert
	#define dbg(...) cerr << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
	#define chk(...) if (!(__VA_ARGS__)) cerr << "Line(" << __LINE__ << ") -> function(" \
		 << __FUNCTION__  << ") -> CHK FAILED: (" << #__VA_ARGS__ << ")" << "\n", exit(0);
#else
	#define dbg(...) 0
	#define chk(...) 0
#endif

// FILE I/O
void setIn(str s) { freopen(s.c_str(),"r",stdin); }
void setOut(str s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { cin.tie(0)->sync_with_stdio(0); }
void setIO(str s = "") {
	unsyncIO();
	// cin.exceptions(cin.failbit); 
	// throws exception when do smth illegal
	// ex. try to read letter into int
	if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

vector<vi> dat(1000);
vector<pair<int, pi>> edges;
vector<vi> dp(1000, vi(1024));
vi ans(1000);

	int N, M; vector<vi> par, adj; vi depth;
	void init(int _N) {  N = _N;
		int d = 1; while ((1<<d) < N) d++;
		par.assign(d,vi(N)); adj.rsz(N); depth.rsz(N);
	}
	void ae(int x, int y) { adj[x].pb(y), adj[y].pb(x); }
	void dfs(int x = 0) {
		FOR(i,1,sz(par)) par[i][x] = par[i-1][par[i-1][x]];
		trav(y,adj[x]) if (y != par[0][x])
			depth[y] = depth[par[0][y]=x]+1, dfs(y);
	}
	void gen(int R = 0) { par[0][R] = R; dfs(R); }
	int jmp(int x, int d) {
		F0R(i,sz(par)) if ((d>>i)&1) x = par[i][x];
		return x; }
	int lca(int x, int y) {
		if (depth[x] < depth[y]) swap(x,y);
		x = jmp(x,depth[x]-depth[y]); if (x == y) return x;
		R0F(i,sz(par)) {
			int X = par[i][x], Y = par[i][y];
			if (X != Y) x = X, y = Y;
		}
		return par[0][x];
	}
	int dist(int x, int y) { // # edges on path
		return depth[x]+depth[y]-2*depth[lca(x,y)]; }

void solve(int curr){
	trav(a, adj[curr])
		solve(a);
	int n = sz(adj[curr]);
	vpi Q[(1 << n)];
	trav(a, dat[curr]){
		auto b = edges[a];
		int u = b.s.f, v = b.s.s;
		int LCA = lca(u, v);
		int mask = 0;
		int val = 0;
		if(LCA != u){
			int temp = jmp(u, depth[u] - depth[LCA] - 1);
			F0R(c, n)
				if(temp == adj[curr][c])
					mask |= (1 << c);
			val += ans[u];
			int last = u;
			u = par[0][u];
			while(u != LCA){
				int MASK = 0;
				F0R(c, sz(adj[u]))
					if(last == adj[u][c])
						MASK = (1 << c);
				val += dp[u][((1 << sz(adj[u])) - 1) ^ MASK];
				last = u;
				u = par[0][u];
			}
		}
		if(LCA != v){
			int temp = jmp(v, depth[v] - depth[LCA] - 1);
			F0R(c, n)
				if(temp == adj[curr][c])
					mask |= (1 << c);
			val += ans[v];
			int last = v;
			v = par[0][v];
			while(v != LCA){
				int MASK = 0;
				F0R(c, sz(adj[v]))
					if(last == adj[v][c])
						MASK = (1 << c);
				val += dp[v][((1 << sz(adj[v])) - 1) ^ MASK];
				last = v;
				v = par[0][v];
			}
		}
		val += b.f;
		F0R(c, (1 << n))
			if((c & mask) == mask)
				Q[c].pb({val, mask});
	}
	F0R(a, (1 << n)){
		F0R(b, n)
			if(a & (1 << b))
				dp[curr][a] += ans[adj[curr][b]];
		trav(b, Q[a]){
			int last = a ^ b.s;
			int mask = b.s;
			int sub = ans[adj[curr][log2(mask & -mask)]];
			mask -= mask & (-mask);
			if(mask)
				sub += ans[adj[curr][log2(mask)]];
			dp[curr][a] = max(dp[curr][a], dp[curr][last] + b.f);
		}
		ans[curr] = max(ans[curr], dp[curr][a]);
	}
}

void prep(int curr, int par){
	trav(a, adj[curr]){
		adj[a].erase(find(all(adj[a]), curr));
		prep(a, curr);
	}
}

int main(){
	setIO();
	cin >> N >> M;
	init(N);
	int tot = 0;
	vector<pair<int, pi>> tedges;
	F0R(a, M){
		int A, B, C;
		cin >> A >> B >> C;
		tot += C;
		A--, B--;
		if(C)
			tedges.pb({C, {A, B}});
		else
			ae(A, B);
	}
	gen();
	trav(a, tedges)
		if(dist(a.s.f, a.s.s) % 2 == 0)
			edges.pb(a);
	F0R(a, sz(edges))
		dat[lca(edges[a].s.f, edges[a].s.s)].pb(a);
	prep(0, -1);
	solve(0);
	cout << (tot - ans[0]) << endl;
	// you should actually read the stuff at the bottom
}

/* stuff you should look for
	* int overflow, array bounds
	* special cases (n=1?)
	* do smth instead of nothing and stay organized
	* WRITE STUFF DOWN
	* DON'T GET STUCK ON ONE APPROACH
*/

Compilation message (stderr)

training.cpp: In function 'void setIn(str)':
training.cpp:183:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  183 | void setIn(str s) { freopen(s.c_str(),"r",stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
training.cpp: In function 'void setOut(str)':
training.cpp:184:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  184 | void setOut(str s) { freopen(s.c_str(),"w",stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 7 / 7
• Subtask 5: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 9 / 9
• Subtask 10: 9 / 9
• Subtask 11: 9 / 9