結果
| 問題 |
No.798 コレクション
|
| コンテスト | |
| ユーザー |
 koyumeishi
|
| 提出日時 | 2019-03-15 22:43:57 |
| 言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
TLE
|
| 実行時間 | - |
| コード長 | 22,109 bytes |
| コンパイル時間 | 2,551 ms |
| コンパイル使用メモリ | 153,476 KB |
| 実行使用メモリ | 229,644 KB |
| 最終ジャッジ日時 | 2024-07-01 21:18:47 |
| 合計ジャッジ時間 | 6,231 ms |
|
ジャッジサーバーID （参考情報） |
judge5 / judge2 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 10 TLE * 1 -- * 12 |
ソースコード
#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <functional>
#include <set>
#include <ctime>
#include <random>
#include <chrono>
#include <cassert>
#include <tuple>
#include <utility>
using namespace std;
namespace {
using Integer = long long; //__int128;
template<class T, class S> istream& operator >> (istream& is, pair<T,S>& p){return is >> p.first >> p.second;}
template<class T> istream& operator >> (istream& is, vector<T>& vec){for(T& val: vec) is >> val; return is;}
template<class T> istream& operator , (istream& is, T& val){ return is >> val;}
template<class T, class S> ostream& operator << (ostream& os, const pair<T,S>& p){return os << p.first << " " << p.second;}
template<class T> ostream& operator << (ostream& os, const vector<T>& vec){for(size_t i=0; i<vec.size(); i++) os << vec[i] << (i==vec.size()-1?"":" "); return os;}
template<class T> ostream& operator , (ostream& os, const T& val){ return os << " " << val;}
template<class H> void print(const H& head){ cout << head; }
template<class H, class ... T> void print(const H& head, const T& ... tail){ cout << head << " "; print(tail...); }
template<class ... T> void println(const T& ... values){ print(values...); cout << endl; }
template<class H> void eprint(const H& head){ cerr << head; }
template<class H, class ... T> void eprint(const H& head, const T& ... tail){ cerr << head << " "; eprint(tail...); }
template<class ... T> void eprintln(const T& ... values){ eprint(values...); cerr << endl; }
class range{ Integer start_, end_, step_; public: struct range_iterator{ Integer val, step_; range_iterator(Integer v, Integer step) : val(v), step_(step) {} Integer operator * (){return val;} void operator ++ (){val += step_;} bool operator != (range_iterator& x){return step_ > 0 ? val < x.val : val > x.val;} }; range(Integer len) : start_(0), end_(len), step_(1) {} range(Integer start, Integer end) : start_(start), end_(end), step_(1) {} range(Integer start, Integer end, Integer step) : start_(start), end_(end), step_(step) {} range_iterator begin(){ return range_iterator(start_, step_); } range_iterator end(){ return range_iterator( end_, step_); } };
inline string operator "" _s (const char* str, size_t size){ return move(string(str)); }
constexpr Integer my_pow(Integer x, Integer k, Integer z=1){return k==0 ? z : k==1 ? z*x : (k&1) ? my_pow(x*x,k>>1,z*x) : my_pow(x*x,k>>1,z);}
constexpr Integer my_pow_mod(Integer x, Integer k, Integer M, Integer z=1){return k==0 ? z%M : k==1 ? z*x%M : (k&1) ? my_pow_mod(x*x%M,k>>1,M,z*x%M) : my_pow_mod(x*x%M,k>>1,M,z);}
constexpr unsigned long long operator "" _ten (unsigned long long value){ return my_pow(10,value); }
inline int k_bit(Integer x, int k){return (x>>k)&1;} //0-indexed
mt19937 mt(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count());
template<class T> string join(const vector<T>& v, const string& sep){ stringstream ss; for(size_t i=0; i<v.size(); i++){ if(i>0) ss << sep; ss << v[i]; } return ss.str(); }
inline string operator * (string s, int k){ string ret; while(k){ if(k&1) ret += s; s += s; k >>= 1; } return ret; }
}
constexpr long long mod = 9_ten + 7;
// min cost flow
// https://min-25.hatenablog.com/entry/2017/08/12/162908
#define _rep(_1, _2, _3, _4, name, ...) name
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, a, b) rep4(i, a, b, 1)
#define rep4(i, a, b, c) for (int i = int(a); i < int(b); i += int(c))
#define rep(...) _rep(__VA_ARGS__, rep4, rep3, rep2, _)(__VA_ARGS__)
using namespace std;
using i64 = long long;
template <typename T>
struct BinaryHeap {
struct node {
bool operator < (const node& rhs) const { return data < rhs.data; }
T data;
int id;
};
BinaryHeap(int N) : size(0) {
nodes = new node[N + 1];
indices = new int[N];
}
~BinaryHeap() {
delete [] nodes;
delete [] indices;
}
void swap_node(int a, int b) {
swap(nodes[a], nodes[b]);
indices[nodes[a].id] = a;
indices[nodes[b].id] = b;
}
void down_heap(int pos) {
for (int k = pos, nk = k; 2 * k <= size; k = nk) {
if (nodes[2 * k] < nodes[nk]) nk = 2 * k;
if (2 * k + 1 <= size && nodes[2 * k + 1] < nodes[nk]) nk = 2 * k + 1;
if (nk == k) break;
swap_node(k, nk);
}
}
void up_heap(int pos) {
for (int k = pos; k > 1 && nodes[k] < nodes[k >> 1]; k >>= 1) {
swap_node(k, k >> 1);
}
}
node get() const {
assert(size >= 1);
return nodes[1];
}
void pop(int pos=1) {
nodes[pos] = nodes[size--];
indices[nodes[pos].id] = pos;
down_heap(pos);
}
void erase(int id) {
pop(indices[id]);
}
void update(int id, T v) {
bool up = (v <= nodes[indices[id]].data);
nodes[indices[id]].data = v;
if (up) up_heap(indices[id]);
else down_heap(indices[id]);
}
void push(int id, T v) {
indices[id] = ++size;
nodes[size] = {v, id};
up_heap(size);
}
void valid() {
bool ok = true;
rep(i, 1, size + 1) {
if (2 * i + 0 <= size) ok &= nodes[i].data <= nodes[2 * i].data;
if (2 * i + 1 <= size) ok &= nodes[i].data <= nodes[2 * i + 1].data;
}
assert(ok);
}
int size;
node* nodes;
int* indices;
};
template <typename input_edge_t, typename weight1_t, typename weight1_sum_t>
struct YoungTarjanOrlinMCR {
using weight2_t = int;
using weight2_sum_t = int;
using ratio_t = double;
static constexpr ratio_t inf = 9e18;
struct node {
node() : par(-1), prev(-1), next(-1), head(-1), eid(-1) {}
int par, prev, next, head, eid;
};
struct edge {
int from, to;
weight1_t w1;
// weight2_t w2;
weight1_t weight1() const { return w1; }
weight2_t weight2() const { return 1; }
};
YoungTarjanOrlinMCR(int N, const vector<input_edge_t>& E)
: N(N), ofs(N + 1), rofs(N + 1), edges(E.size()), redges(E.size()) {
nodes = new node[N + 1];
for (auto& e : E) ofs[e.from + 1] += 1, rofs[e.to + 1] += 1;
rep(i, 1, N + 1) ofs[i] += ofs[i - 1];
rep(i, 1, N + 1) rofs[i] += rofs[i - 1];
rep(i, E.size()) {
auto e = E[i];
redges[rofs[e.to]++] = ofs[e.from];
edges[ofs[e.from]++] = {e.from, e.to, e.weight1()};
}
rep(i, N) ofs[N - i] = ofs[N - 1 - i];
rep(i, N) rofs[N - i] = rofs[N - 1 - i];
ofs[0] = rofs[0] = 0;
}
~YoungTarjanOrlinMCR() {
delete [] nodes;
}
// node operations
void link(int u, int v, int eid) {
if (nodes[u].head < 0) {
nodes[u].head = v;
} else {
int w = nodes[u].head;
nodes[u].head = nodes[w].prev = v;
nodes[v].next = w;
}
nodes[v].par = u;
nodes[v].eid = eid;
}
void cut(int u, int v) {
int& uh = nodes[u].head;
int& vp = nodes[v].prev, &vn = nodes[v].next;
if (uh == v) {
if (vn < 0) uh = -1;
else uh = vn, nodes[vn].prev = -1;
} else {
if (vn < 0) nodes[vp].next = -1;
else nodes[vp].next = vn, nodes[vn].prev = vp;
}
vp = vn = -1;
}
void cut_and_link(int u, int v, int eid) {
assert(nodes[v].par >= 0);
cut(nodes[v].par, v);
link(u, v, eid);
}
int tabulate_subtree_nodes(int u, int size, vector<int>& vs, vector<bool>& has) const {
has[vs[size++] = u] = true;
for (int v = nodes[u].head; v >= 0; v = nodes[v].next) {
size = tabulate_subtree_nodes(v, size, vs, has);
}
return size;
}
void print_subtree(int root, int indent=0) const {
rep(i, indent) putchar(' ');
printf("%d\n", root);
for (int v = nodes[root].head; v >= 0; v = nodes[v].next) {
print_subtree(v, indent + 1);
}
}
//
void trace_back_to_floored_ratio(weight1_t floored_ratio, vector< pair<ratio_t, int> >& update_log) {
for (int i = update_log.size() - 1; i >= 0; --i) {
if (update_log[i].first <= floored_ratio) break;
int eid = update_log[i].second;
int u = (eid < 0) ? N : edges[eid].from;
int v = (eid < 0) ? ~eid : edges[eid].to;
cut_and_link(u, v, eid);
}
}
void calc_potential(int u, weight1_t lambda) {
for (int v = nodes[u].head; v >= 0; v = nodes[v].next) {
int eid = nodes[v].eid;
weight1[v] = weight1[u] + (eid < 0 ? 0 : edges[eid].weight1());
weight1[v] -= (eid < 0 ? 1 : edges[eid].weight2()) * lambda;
calc_potential(v, lambda);
}
}
ratio_t cycle_ratio(int eid) const {
auto& e = edges[eid];
int u = e.from, v = e.to;
auto delta_w2 = weight2[u] + e.weight2() - weight2[v];
if (delta_w2 <= 0) return inf;
auto delta_w1 = weight1[u] + e.weight1() - weight1[v];
return ratio_t(delta_w1) / delta_w2;
}
void verify_potential(const weight1_t ratio) const {
rep(u, N) rep(eid, ofs[u], ofs[u + 1]) {
auto d = weight1[u] + edges[eid].weight1() - edges[eid].weight2() * ratio;
assert(d >= weight1[edges[eid].to]);
}
}
void reconstruct_sp_tree(int eid, vector<int>& subtree_nodes, int subtree_size) {
auto& e = edges[eid];
int u = e.from, v = e.to;
auto dw1 = weight1[u] + e.weight1() - weight1[v];
auto dw2 = weight2[u] + e.weight2() - weight2[v];
rep(i, subtree_size) {
int u = subtree_nodes[i];
weight1[u] += dw1, weight2[u] += dw2;
}
cut_and_link(u, v, eid);
}
ratio_t minimum_cycle_ratio(bool use_integral_ratio=false) {
const int root = N;
rep(i, N + 1) nodes[i] = node();
rep(i, N) link(root, i, ~i);
weight1.assign(N + 1, 0);
weight2.assign(N + 1, 1); weight2[root] = 0;
vector<int> best_eid(N + 1, -1);
vector<ratio_t> min_ratios(edges.size(), inf);
rep(u, N) rep(eid, ofs[u], ofs[u + 1]) {
int v = edges[eid].to;
min_ratios[eid] = cycle_ratio(eid);
if (best_eid[v] < 0 || min_ratios[eid] < min_ratios[best_eid[v]]) {
best_eid[v] = eid;
}
}
auto heap = BinaryHeap<ratio_t>(N + 1); heap.push(N, inf);
rep(v, N) if (best_eid[v] >= 0) heap.push(v, min_ratios[best_eid[v]]);
vector<bool> subtree_has(N);
vector<int> subtree_nodes(N);
vector< pair<ratio_t, int> > change_log;
auto curr_ratio = inf;
while (1) {
auto node = heap.get();
curr_ratio = node.data;
if (curr_ratio == inf) break;
auto& e = edges[best_eid[node.id]];
int subtree_root = e.to;
int subtree_size = tabulate_subtree_nodes(subtree_root, 0, subtree_nodes, subtree_has);
if (subtree_has[e.from]) break;
change_log.emplace_back(curr_ratio, nodes[subtree_root].eid);
reconstruct_sp_tree(best_eid[subtree_root], subtree_nodes, subtree_size);
auto update_ratio = [&](int v, int eid) {
auto best_ratio = min_ratios[best_eid[v]];
if ((min_ratios[eid] = cycle_ratio(eid)) < best_ratio) {
heap.update(v, min_ratios[best_eid[v] = eid]);
}
};
rep(i, subtree_size) {
int u = subtree_nodes[i];
// u -> v (v is not in the subtree)
rep(eid, ofs[u], ofs[u + 1]) {
int v = edges[eid].to;
if (!subtree_has[v]) update_ratio(v, eid);
}
// u <- v
if (!subtree_has[edges[best_eid[u]].from]) {
// check all the neighbors of u.
min_ratios[best_eid[u]] = inf;
rep(reid, rofs[u], rofs[u + 1]) update_ratio(u, redges[reid]);
heap.update(u, min_ratios[best_eid[u]]);
} else {
// check the the neighbors of u that is not in the subtree.
rep(reid, rofs[u], rofs[u + 1]) {
auto eid = redges[reid];
if (subtree_has[edges[eid].from]) continue;
update_ratio(u, eid);
}
}
}
rep(i, subtree_size) subtree_has[subtree_nodes[i]] = false;
}
if (use_integral_ratio) {
weight1_t floored_ratio = -ceil(-curr_ratio);
trace_back_to_floored_ratio(floored_ratio, change_log);
calc_potential(N, floored_ratio);
// verify_potential(floored_ratio);
return floored_ratio;
} else {
return curr_ratio;
}
}
int N;
node* nodes;
vector<int> ofs, rofs;
vector<edge> edges;
vector<weight1_sum_t> weight1;
vector<weight2_sum_t> weight2;
vector<int> redges;
};
namespace circulation {
using cap_t = int;
using cap_sum_t = i64;
using cost_t = i64; // |V| C
using cost_sum_t = i64; // |V|^2 C should be < 2^63.
class Dinic {
using cap_t = cap_sum_t;
static const cap_t inf = 9e18;
struct edge {
int to, rev;
cap_t cap;
int eid;
};
public:
Dinic() {}
Dinic(int N) : N(N), edges(N) {}
void add_directed_edge(int u, int v, cap_t cap, int eid) {
edges[u].push_back({v, int(edges[v].size()), cap, eid});
edges[v].push_back({u, int(edges[u].size() - 1), 0, -1});
}
bool construct(int s, int t, int* que) {
dist.assign(N, -1); dist[s] = 0;
que[0] = s;
for (int qh = 0, qt = 1; qh < qt; ) {
int u = que[qh++];
if (u == t) break;
for (auto& e : edges[u]) if (dist[e.to] < 0 && e.cap > 0) {
dist[e.to] = dist[u] + 1;
que[qt++] = e.to;
}
}
return dist[t] >= 0;
}
// seems faster
cap_t block_flow(int u, int t, cap_t f) {
if (u == t) return f;
for (int& ei = last[u]; ei < int(edges[u].size()); ++ei) {
auto& e = edges[u][ei];
if (e.cap == 0 || dist[e.to] <= dist[u]) continue;
cap_t aug = block_flow(e.to, t, min(f, e.cap));
if (aug == 0) continue;
e.cap -= aug; edges[e.to][e.rev].cap += aug;
f -= aug;
return aug;
}
return 0;
}
cap_sum_t block_flow_all(int u, int t, cap_t f) {
if (u == t) return f;
cap_sum_t ret = 0;
for (int& ei = last[u]; ei < int(edges[u].size()); ++ei) {
auto& e = edges[u][ei];
if (e.cap == 0 || dist[e.to] <= dist[u]) continue;
cap_t aug = block_flow(e.to, t, min(f, e.cap));
if (aug == 0) continue;
e.cap -= aug; edges[e.to][e.rev].cap += aug;
f -= aug; ret += aug;
if (f == 0) break;
}
return ret;
}
cap_sum_t maximum_flow(int s, int t) {
if (s == t) return 0;
cap_sum_t flow = 0;
vector<int> que(N);
last.resize(N);
while (construct(s, t, que.data())) {
fill_n(last.begin(), N, 0);
// flow += block_flow_all(s, t, inf);
for (cap_t f; (f = block_flow(s, t, inf)) > 0; flow += f);
}
return flow;
}
int N;
vector< vector<edge> > edges;
private:
vector<int> last, dist;
};
class MinimumCostCirculation {
static constexpr cost_t inf = 9e18;
struct edge {
bool operator < (const edge& rhs) const {
return from < rhs.from || (from == rhs.from && to < rhs.to);
}
cost_t weight1() const {
return cost;
}
int from, to;
cap_t b, c, flow;
cost_t cost;
int rev;
};
public:
MinimumCostCirculation(int N, bool avoid_parallel_edges=false) :
N(N), avoid_parallel_edges(avoid_parallel_edges) {}
void add_directed_edge(int u, int v, cap_t b, cap_t c, cost_t cost) {
assert(u != v);
bool rev = 0;
if (avoid_parallel_edges) {
rev = u > v;
if (rev) swap(u, v);
}
edges.push_back({u, v, b, c, 0, cost, rev});
}
void convert_to_simple_graph() {
sort(edges.begin(), edges.end());
int edge_count = edges.size();
for (int ei = 0; ei < edge_count; ) {
int u = edges[ei].from, v = edges[ei].to;
if (edges[ei].rev) swap(edges[ei].from, edges[ei].to);
for (ei += 1; ei < edge_count && edges[ei].from == u && edges[ei].to == v; ++ei) {
int s = u, t = v;
if (edges[ei].rev) swap(s, t);
auto b = edges[ei].b, c = edges[ei].c;
edges[ei] = {s, N, b, c, 0, edges[ei].cost, 0};
edges.push_back({N, t, b, c, 0, 0, 0});
original_edges.push_back({s, t});
++N;
}
}
}
bool has_feasible_circulation() {
auto dinic = Dinic(N + 2);
vector<cap_sum_t> capacity(2 * N, 0);
rep(ei, edges.size()) {
auto& e = edges[ei];
int u = e.from, v = e.to;
dinic.add_directed_edge(u, v, e.c - e.b, ei);
if (e.b > 0) capacity[v] += e.b, capacity[u + N] += e.b;
else capacity[u] += -e.b, capacity[v + N] += -e.b;
}
rep(i, N) dinic.add_directed_edge(N, i, capacity[i], -1);
rep(i, N) dinic.add_directed_edge(i, N + 1, capacity[i + N], -1);
auto max_flow = dinic.maximum_flow(N, N + 1);
cap_sum_t s = 0;
rep(i, N) s += capacity[i];
if (max_flow < s) return false;
rep(u, dinic.N) for (auto& e : dinic.edges[u]) if (e.eid >= 0) {
edges[e.eid].flow = edges[e.eid].c - e.cap;
}
return true;
}
void antisymmetrize() {
vector<edge> curr_edges = edges;
ofs.assign(N + 1, 0);
edges.resize(2 * curr_edges.size());
for (auto& e : curr_edges) ofs[e.from + 1]++, ofs[e.to + 1]++;
rep(i, N) ofs[i + 1] += ofs[i];
for (auto& e : curr_edges) {
e.rev = ofs[e.to]; edges[ofs[e.from]] = e;
edges[ofs[e.to]++] = {e.to, e.from, -e.c, -e.b, -e.flow, -e.cost, ofs[e.from]++};
}
rep(i, N) ofs[N - i] = ofs[N - 1 - i];
ofs[0] = 0;
}
vector<edge> residual_graph(const vector<edge>& edges) {
vector<edge> residual;
for (auto& e : edges) if (e.c > e.flow) residual.push_back(e);
return residual;
}
void enlarge_edge_cost(const int multiplier) {
for (auto& e : edges) e.cost *= multiplier;
}
void refine(const cost_t eps, vector<cost_sum_t>& potential) {
/*
complexity: O(|V|^2 |E|)
- relabel: O(|V|^2)
- saturating push: O(|V||E|)
- non-saturating push: O(|V|^2 |E|)
*/
assert(eps >= 1);
auto cost_p = [&](const edge& e) {
return e.cost + potential[e.from] - potential[e.to];
};
// e.flow := residue
for (auto& e : edges) {
if (cost_p(e) < 0) e.flow = 0, edges[e.rev].flow = e.c - e.b;
else if (cost_p(e) == 0) e.flow = e.c - e.flow;
}
vector<cap_sum_t> excess(N, 0);
for (auto& e : edges) excess[e.to] += e.c - e.flow;
// practically, stack<int> seems better than queue<int>.
vector<int> admissible_vertices; admissible_vertices.reserve(N);
rep(u, N) if (excess[u] > 0) admissible_vertices.push_back(u);
auto residue = [&](const edge& e) {
return e.flow;
};
auto push = [&](int u, edge& e, cap_t df) {
e.flow -= df; edges[e.rev].flow += df;
excess[e.to] += df; excess[u] -= df;
if (excess[e.to] > 0 && excess[e.to] - df <= 0) {
admissible_vertices.push_back(e.to);
}
};
auto relabel = [&](int u, cost_t delta) {
potential[u] -= delta + eps;
};
// simpler version of push look-ahead.
auto relabel_in_advance = [&](int u) {
if (excess[u] != 0) return false;
auto delta = inf;
rep(ei, ofs[u], ofs[u + 1]) {
auto& e = edges[ei];
if (residue(e) > 0) {
if (cost_p(e) < 0) return false;
else delta = min(delta, cost_p(e));
}
}
relabel(u, delta);
return true;
};
while (!admissible_vertices.empty()) {
auto u = admissible_vertices.back(); admissible_vertices.pop_back();
bool rel = true;
auto delta = inf;
rep(ei, ofs[u], ofs[u + 1]) {
auto& e = edges[ei];
if (residue(e) > 0) {
if (cost_p(e) < 0) {
if (relabel_in_advance(e.to)) {
--ei; continue;
}
cap_t df = min(excess[u], cap_sum_t(residue(e)));
push(u, e, df);
if (excess[u]) continue;
rel = false;
break;
} else delta = min(delta, cost_p(e));
}
}
if (rel) relabel(u, delta), admissible_vertices.push_back(u);
}
// e.flow := (real) flow
for (auto& e : edges) e.flow = e.c - e.flow;
// for (auto& e : edges) assert(e.b <= e.flow && e.flow <= e.c);
// rep(i, N) assert(excess[i] == 0);
}
pair<bool, cost_sum_t> minimum_cost_circulation() {
/*
complexity: O(|V|^2 |E| \log(|V|C))
(Practically, it runs much faster.)
*/
assert(edges.size() > 0);
if (avoid_parallel_edges) convert_to_simple_graph();
if (!has_feasible_circulation()) return {false, -1};
const int cost_multiplier = 2 << __lg(N); // should be > |V|
enlarge_edge_cost(cost_multiplier);
antisymmetrize();
while (1) {
auto yto = YoungTarjanOrlinMCR<edge, cost_t, cost_sum_t>(N, residual_graph(edges));
cost_t eps = -yto.minimum_cycle_ratio(true); // integral ratio
if (eps <= 0) break;
// auto time_beg = clock();
refine(eps / 2, yto.weight1);
// fprintf(stderr, "refine: |V| = %d, |E| = %d, eps = %lld, elapsed: %.6f sec.\n",
// N, int(edges.size()), eps, double(clock() - time_beg) / CLOCKS_PER_SEC);
}
cost_sum_t ret = 0;
for (auto& e : edges) ret += (e.cost / cost_multiplier) * e.flow;
return {true, ret / 2};
}
private:
int N;
vector< pair<int, int> > original_edges;
vector<int> ofs;
vector<edge> edges;
bool avoid_parallel_edges;
};
} // namespace circulation
int main(){
int n;
cin >> n;
vector<pair<int,int>> v(n);
cin >> v;
// Min_Cost_Flow<long long> f(n + n + 1 + 2, 1000000000);
// MCC f(n+n+3);
circulation::MinimumCostCirculation f(n+n+3);
int source = n+n+1;
int sink = source+1;
int odd = n+n;
// f.add_edge(odd, sink, n/3, 0);
f.add_directed_edge(odd, sink, n/3, n/3, 0);
for(int i=0; i<n; i++){
// f.add_edge(source, i, 1, v[i].first);
f.add_directed_edge(source, i, 0, 1, v[i].first);
for(int j=0; j<n-n/3; j++){
// f.add_edge(i, n+j, 1, v[i].second * j);
f.add_directed_edge(i, n+j, 0, 1, v[i].second * j);
}
// f.add_edge(i, odd, 1, -v[i].first);
f.add_directed_edge(i, odd, 0, 1, -v[i].first);
}
for(int i=0; i<n-n/3; i++){
// f.add_edge(n+i, sink, 1, 0);
f.add_directed_edge(n+i, sink, 1, 1, 0);
}
f.add_directed_edge(sink, source, n, n, 0);
// long long cost = f.min_cost_flow(source, sink, n);
long long cost = f.minimum_cost_circulation().second;
println(cost);
return 0;
}