結果
| 問題 |
No.2736 About half
|
| コンテスト | |
| ユーザー |
 hotman78
|
| 提出日時 | 2024-04-20 10:06:06 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 2 ms / 2,000 ms |
| コード長 | 15,435 bytes |
| コンパイル時間 | 2,873 ms |
| コンパイル使用メモリ | 225,876 KB |
| 最終ジャッジ日時 | 2025-02-21 06:05:31 |
|
ジャッジサーバーID （参考情報） |
judge2 / judge3 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 15 |
ソースコード
// author: hotman78
// date: 2024/04/20-10:05:39
// --- begin raw code -----------------
// #include"cpplib/util/template.hpp"
// #include<atcoder/mincostflow.hpp>
// using namespace atcoder;
// void solve(){
// lint a,b;
// cin>>a>>b;
// cout<<((a>b*2||b>a*2)?"No":"Yes")<<endl;
// }
//
// int main(){
// solve();
// // lint t;cin>>t;while(t--)solve();
// }
// --- end raw code -----------------
#line 2 "cpplib/util/template.hpp"
#ifdef LOCAL
#define _GLIBCXX_DEBUG
#endif
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
// #pragma GCC target("avx2")
#include <bits/stdc++.h>
using namespace std;
#line 1 "cpplib/util/ioutil.hpp"
// template <class Head,class... Args>
// std::ostream& output(std::ostream& out,const Head& head,const Args&... args){
// out>>head;
// return output(head,args...);
// }
// template <class Head>
// std::ostream& output(std::ostream& out,const Head& head){
// out>>head;
// return out;
// }
template <typename T, typename E>
std::ostream &operator<<(std::ostream &out, std::pair<T, E> v) {
out << "(" << v.first << "," << v.second << ")";
return out;
}
// template <class... Args>
// ostream& operator<<(ostream& out,std::tuple<Args...>v){
// std::apply(output,v);
// return out;
// }
#line 11 "cpplib/util/template.hpp"
struct __INIT__ {
__INIT__() {
cin.tie(0);
ios::sync_with_stdio(false);
cout << fixed << setprecision(15);
}
} __INIT__;
typedef long long lint;
constexpr long long INF = 1LL << 60;
constexpr int IINF = 1 << 30;
constexpr double EPS = 1e-10;
#ifndef REACTIVE
#define endl '\n';
#endif
typedef vector<lint> vec;
typedef vector<vector<lint>> mat;
typedef vector<vector<vector<lint>>> mat3;
typedef vector<string> svec;
typedef vector<vector<string>> smat;
template <typename T> using V = vector<T>;
template <typename T> using VV = V<V<T>>;
#define output(t) \
{ \
bool f = 0; \
for (auto val : (t)) { \
cout << (f ? " " : "") << val; \
f = 1; \
} \
cout << endl; \
}
#define output2(t) \
{ \
for (auto i : t) \
output(i); \
}
#define debug(t) \
{ \
bool f = 0; \
for (auto i : t) { \
cerr << (f ? " " : "") << i; \
f = 1; \
} \
cerr << endl; \
}
#define debug2(t) \
{ \
for (auto i : t) \
debug(i); \
}
#define loop(n) for (long long _ = 0; _ < (long long)(n); ++_)
#define _overload4(_1, _2, _3, _4, name, ...) name
#define __rep(i, a) repi(i, 0, a, 1)
#define _rep(i, a, b) repi(i, a, b, 1)
#define repi(i, a, b, c) \
for (long long i = (long long)(a); i < (long long)(b); i += c)
#define rep(...) _overload4(__VA_ARGS__, repi, _rep, __rep)(__VA_ARGS__)
#define _overload3_rev(_1, _2, _3, name, ...) name
#define _rep_rev(i, a) repi_rev(i, 0, a)
#define repi_rev(i, a, b) \
for (long long i = (long long)(b)-1; i >= (long long)(a); --i)
#define rrep(...) _overload3_rev(__VA_ARGS__, repi_rev, _rep_rev)(__VA_ARGS__)
#define all(n) begin(n), end(n)
template <typename T, typename E> bool chmin(T &s, const E &t) {
bool res = s > t;
s = min<T>(s, t);
return res;
}
template <typename T, typename E> bool chmax(T &s, const E &t) {
bool res = s < t;
s = max<T>(s, t);
return res;
}
const vector<lint> dx = {1, 0, -1, 0, 1, 1, -1, -1};
const vector<lint> dy = {0, 1, 0, -1, 1, -1, 1, -1};
#define SUM(v) accumulate(all(v), 0LL)
#if __cplusplus >= 201703L
template <typename T, typename... Args>
auto make_vector(T x, int arg, Args... args) {
if constexpr (sizeof...(args) == 0)
return vector<T>(arg, x);
else
return vector(arg, make_vector<T>(x, args...));
}
#endif
#define bit(n, a) ((n >> a) & 1)
#define extrep(v, ...) for (auto v : make_mat_impl({__VA_ARGS__}))
vector<vector<long long>> make_mat_impl(vector<long long> v) {
if (v.empty())
return vector<vector<long long>>(1, vector<long long>());
long long n = v.back();
v.pop_back();
vector<vector<long long>> ret;
vector<vector<long long>> tmp = make_mat_impl(v);
for (auto e : tmp)
for (long long i = 0; i < n; ++i) {
ret.push_back(e);
ret.back().push_back(i);
}
return ret;
}
using graph = vector<vector<int>>;
template <typename T> using graph_w = vector<vector<pair<int, T>>>;
#if __cplusplus >= 201703L
constexpr inline long long powll(long long a, long long b) {
long long res = 1;
while (b--)
res *= a;
return res;
}
#endif
template <typename T, typename E>
pair<T, E> &operator+=(pair<T, E> &s, const pair<T, E> &t) {
s.first += t.first;
s.second += t.second;
return s;
}
template <typename T, typename E>
pair<T, E> &operator-=(pair<T, E> &s, const pair<T, E> &t) {
s.first -= t.first;
s.second -= t.second;
return s;
}
template <typename T, typename E>
pair<T, E> operator+(const pair<T, E> &s, const pair<T, E> &t) {
auto res = s;
return res += t;
}
template <typename T, typename E>
pair<T, E> operator-(const pair<T, E> &s, const pair<T, E> &t) {
auto res = s;
return res -= t;
}
#define BEGIN_STACK_EXTEND(size) \
void *stack_extend_memory_ = malloc(size); \
void *stack_extend_origin_memory_; \
char *stack_extend_dummy_memory_ = (char *)alloca( \
(1 + (int)(((long long)stack_extend_memory_) & 127)) * 16); \
*stack_extend_dummy_memory_ = 0; \
asm volatile("mov %%rsp, %%rbx\nmov %%rax, %%rsp" \
: "=b"(stack_extend_origin_memory_) \
: "a"((char *)stack_extend_memory_ + (size)-1024));
#define END_STACK_EXTEND \
asm volatile("mov %%rax, %%rsp" ::"a"(stack_extend_origin_memory_)); \
free(stack_extend_memory_);
int floor_pow(int n) { return n ? 31 - __builtin_clz(n) : 0; }
#line 2 "main.cpp"
#include <algorithm>
#include <cassert>
#include <limits>
#include <queue>
#include <vector>
#include <algorithm>
#include <utility>
#include <vector>
namespace atcoder {
namespace internal {
template <class E> struct csr {
std::vector<int> start;
std::vector<E> elist;
explicit csr(int n, const std::vector<std::pair<int, E>> &edges)
: start(n + 1), elist(edges.size()) {
for (auto e : edges) {
start[e.first + 1]++;
}
for (int i = 1; i <= n; i++) {
start[i] += start[i - 1];
}
auto counter = start;
for (auto e : edges) {
elist[counter[e.first]++] = e.second;
}
}
};
} // namespace internal
} // namespace atcoder
#include <vector>
namespace atcoder {
namespace internal {
template <class T> struct simple_queue {
std::vector<T> payload;
int pos = 0;
void reserve(int n) { payload.reserve(n); }
int size() const { return int(payload.size()) - pos; }
bool empty() const { return pos == int(payload.size()); }
void push(const T &t) { payload.push_back(t); }
T &front() { return payload[pos]; }
void clear() {
payload.clear();
pos = 0;
}
void pop() { pos++; }
};
} // namespace internal
} // namespace atcoder
namespace atcoder {
template <class Cap, class Cost> struct mcf_graph {
public:
mcf_graph() {}
explicit mcf_graph(int n) : _n(n) {}
int add_edge(int from, int to, Cap cap, Cost cost) {
assert(0 <= from && from < _n);
assert(0 <= to && to < _n);
assert(0 <= cap);
assert(0 <= cost);
int m = int(_edges.size());
_edges.push_back({from, to, cap, 0, cost});
return m;
}
struct edge {
int from, to;
Cap cap, flow;
Cost cost;
};
edge get_edge(int i) {
int m = int(_edges.size());
assert(0 <= i && i < m);
return _edges[i];
}
std::vector<edge> edges() { return _edges; }
std::pair<Cap, Cost> flow(int s, int t) {
return flow(s, t, std::numeric_limits<Cap>::max());
}
std::pair<Cap, Cost> flow(int s, int t, Cap flow_limit) {
return slope(s, t, flow_limit).back();
}
std::vector<std::pair<Cap, Cost>> slope(int s, int t) {
return slope(s, t, std::numeric_limits<Cap>::max());
}
std::vector<std::pair<Cap, Cost>> slope(int s, int t, Cap flow_limit) {
assert(0 <= s && s < _n);
assert(0 <= t && t < _n);
assert(s != t);
int m = int(_edges.size());
std::vector<int> edge_idx(m);
auto g = [&]() {
std::vector<int> degree(_n), redge_idx(m);
std::vector<std::pair<int, _edge>> elist;
elist.reserve(2 * m);
for (int i = 0; i < m; i++) {
auto e = _edges[i];
edge_idx[i] = degree[e.from]++;
redge_idx[i] = degree[e.to]++;
elist.push_back({e.from, {e.to, -1, e.cap - e.flow, e.cost}});
elist.push_back({e.to, {e.from, -1, e.flow, -e.cost}});
}
auto _g = internal::csr<_edge>(_n, elist);
for (int i = 0; i < m; i++) {
auto e = _edges[i];
edge_idx[i] += _g.start[e.from];
redge_idx[i] += _g.start[e.to];
_g.elist[edge_idx[i]].rev = redge_idx[i];
_g.elist[redge_idx[i]].rev = edge_idx[i];
}
return _g;
}();
auto result = slope(g, s, t, flow_limit);
for (int i = 0; i < m; i++) {
auto e = g.elist[edge_idx[i]];
_edges[i].flow = _edges[i].cap - e.cap;
}
return result;
}
private:
int _n;
std::vector<edge> _edges;
struct _edge {
int to, rev;
Cap cap;
Cost cost;
};
std::vector<std::pair<Cap, Cost>> slope(internal::csr<_edge> &g, int s,
int t, Cap flow_limit) {
std::vector<std::pair<Cost, Cost>> dual_dist(_n);
std::vector<int> prev_e(_n);
std::vector<bool> vis(_n);
struct Q {
Cost key;
int to;
bool operator<(Q r) const { return key > r.key; }
};
std::vector<int> que_min;
std::vector<Q> que;
auto dual_ref = [&]() {
for (int i = 0; i < _n; i++) {
dual_dist[i].second = std::numeric_limits<Cost>::max();
}
std::fill(vis.begin(), vis.end(), false);
que_min.clear();
que.clear();
size_t heap_r = 0;
dual_dist[s].second = 0;
que_min.push_back(s);
while (!que_min.empty() || !que.empty()) {
int v;
if (!que_min.empty()) {
v = que_min.back();
que_min.pop_back();
} else {
while (heap_r < que.size()) {
heap_r++;
std::push_heap(que.begin(), que.begin() + heap_r);
}
v = que.front().to;
std::pop_heap(que.begin(), que.end());
que.pop_back();
heap_r--;
}
if (vis[v])
continue;
vis[v] = true;
if (v == t)
break;
Cost dual_v = dual_dist[v].first, dist_v = dual_dist[v].second;
for (int i = g.start[v]; i < g.start[v + 1]; i++) {
auto e = g.elist[i];
if (!e.cap)
continue;
Cost cost = e.cost - dual_dist[e.to].first + dual_v;
if (dual_dist[e.to].second - dist_v > cost) {
Cost dist_to = dist_v + cost;
dual_dist[e.to].second = dist_to;
prev_e[e.to] = e.rev;
if (dist_to == dist_v) {
que_min.push_back(e.to);
} else {
que.push_back(Q{dist_to, e.to});
}
}
}
}
if (!vis[t]) {
return false;
}
for (int v = 0; v < _n; v++) {
if (!vis[v])
continue;
dual_dist[v].first -= dual_dist[t].second - dual_dist[v].second;
}
return true;
};
Cap flow = 0;
Cost cost = 0, prev_cost_per_flow = -1;
std::vector<std::pair<Cap, Cost>> result = {{Cap(0), Cost(0)}};
while (flow < flow_limit) {
if (!dual_ref())
break;
Cap c = flow_limit - flow;
for (int v = t; v != s; v = g.elist[prev_e[v]].to) {
c = std::min(c, g.elist[g.elist[prev_e[v]].rev].cap);
}
for (int v = t; v != s; v = g.elist[prev_e[v]].to) {
auto &e = g.elist[prev_e[v]];
e.cap += c;
g.elist[e.rev].cap -= c;
}
Cost d = -dual_dist[s].first;
flow += c;
cost += c * d;
if (prev_cost_per_flow == d) {
result.pop_back();
}
result.push_back({flow, cost});
prev_cost_per_flow = d;
}
return result;
}
};
} // namespace atcoder
using namespace atcoder;
void solve() {
lint a, b;
cin >> a >> b;
cout << ((a > b * 2 || b > a * 2) ? "No" : "Yes") << endl;
}
int main() {
solve();
// lint t;cin>>t;while(t--)solve();
}