#864207 (C++17) No.1981 [Cherry 4th Tune N] アルゴリズムが破滅する例

提出ソース

結果

問題	No.1981 [Cherry 4th Tune N] アルゴリズムが破滅する例
ユーザー	eQe
提出日時	2023-04-29 05:20:14
言語	C++17 (gcc 12.3.0 + boost 1.83.0)
結果	AC
実行時間	3 ms / 2,000 ms
コード長	14,412 bytes
コンパイル時間	9,243 ms
コンパイル使用メモリ	346,804 KB
実行使用メモリ	6,824 KB
最終ジャッジ日時	2024-11-18 04:09:15
合計ジャッジ時間	13,492 ms
ジャッジサーバーID （参考情報）	judge2 / judge1

このコードへのチャレンジ
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テストケース

テストケース表示

入力	結果	実行時間実行使用メモリ
testcase_00	AC	2 ms 6,816 KB
testcase_01	AC	3 ms 6,816 KB
testcase_02	AC	2 ms 6,816 KB
testcase_03	AC	2 ms 6,816 KB
testcase_04	AC	2 ms 6,816 KB
testcase_05	AC	2 ms 6,820 KB
testcase_06	AC	2 ms 6,816 KB
testcase_07	AC	2 ms 6,816 KB
testcase_08	AC	2 ms 6,824 KB
testcase_09	AC	2 ms 6,816 KB
testcase_10	AC	2 ms 6,816 KB
testcase_11	AC	2 ms 6,820 KB
testcase_12	AC	2 ms 6,820 KB
testcase_13	AC	2 ms 6,820 KB
testcase_14	AC	2 ms 6,816 KB
testcase_15	AC	2 ms 6,816 KB
testcase_16	AC	2 ms 6,820 KB
testcase_17	AC	2 ms 6,816 KB
testcase_18	AC	2 ms 6,816 KB
testcase_19	AC	2 ms 6,820 KB
testcase_20	AC	2 ms 6,820 KB
testcase_21	AC	3 ms 6,816 KB
testcase_22	AC	2 ms 6,820 KB
testcase_23	AC	2 ms 6,820 KB
testcase_24	AC	2 ms 6,816 KB
testcase_25	AC	2 ms 6,820 KB
testcase_26	AC	2 ms 6,816 KB
testcase_27	AC	3 ms 6,820 KB
testcase_28	AC	2 ms 6,820 KB
testcase_29	AC	2 ms 6,820 KB
testcase_30	AC	2 ms 6,816 KB
testcase_31	AC	2 ms 6,820 KB
testcase_32	AC	2 ms 6,820 KB
testcase_33	AC	2 ms 6,816 KB
testcase_34	AC	2 ms 6,816 KB
testcase_35	AC	2 ms 6,816 KB
testcase_36	AC	2 ms 6,820 KB
testcase_37	AC	2 ms 6,820 KB
testcase_38	AC	2 ms 6,820 KB
testcase_39	AC	2 ms 6,820 KB
testcase_40	AC	2 ms 6,820 KB
testcase_41	AC	2 ms 6,820 KB
testcase_42	AC	2 ms 6,816 KB
testcase_43	AC	2 ms 6,816 KB
testcase_44	AC	2 ms 6,816 KB
testcase_45	AC	2 ms 6,820 KB
testcase_46	AC	2 ms 6,816 KB
testcase_47	AC	2 ms 6,820 KB
testcase_48	AC	2 ms 6,816 KB

権限があれば一括ダウンロードができます

ソースコード

raw source code

#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<atcoder/all>
#include<bits/stdc++.h>
#define bgn(a) begin(a)
#define rbg(a) rbegin(a)
#define fin(...) exit(pp(__VA_ARGS__))
#define done(...) rr vo(pp(__VA_ARGS__))
#define ep(...) emplace(__VA_ARGS__)
#define eb(...) emplace_back(__VA_ARGS__)
#define ef(...) else if(__VA_ARGS__)
#define el else
#define wh(...) while(__VA_ARGS__)
#define lb(...) lower_bound(__VA_ARGS__)
#define ub(...) upper_bound(__VA_ARGS__)
#define srt(...) sort(al(__VA_ARGS__))
#define rv(...) reverse(al(__VA_ARGS__))
#define rsr(a) srt(a),rv(a)
#define uq(a) srt(a),a.erase(unique(al(a)),end(a))
#define ov3(a,b,c,d,...) d
#define ov4(a,b,c,d,e,...) e
#define ov5(a,b,c,d,e,f,...) f
#define al1(v) bgn(v),end(v)
#define al2(v,b) bgn(v),bgn(v)+b
#define al3(v,a,b) bgn(v)+a,bgn(v)+b
#define al(...) ov3(__VA_ARGS__,al3,al2,al1)(__VA_ARGS__)
#define fo1(b) for(ll ii=0;ii<(ll)(b);ii++)
#define fo2(i,b) for(ll i=0;i<(ll)(b);i++)
#define fo3(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define fo4(i,a,b,c) for(ll i=(ll)(a);i<(ll)(b);i+=(ll)(c))
#define fo(...) ov4(__VA_ARGS__,fo4,fo3,fo2,fo1)(__VA_ARGS__)
#define of2(i,a) for(ll i=(ll)(a)-1;i>=0;i--)
#define of3(i,a,b) for(ll i=(ll)(a)-1;i>=(ll)(b);i--)
#define of4(i,a,b,c) for(ll i=(ll)(a)-1;i>=(ll)(b);i-=(ll)(c))
#define of(...) ov4(__VA_ARGS__,of4,of3,of2)(__VA_ARGS__)
#define fe2(a,v) for(au&&a:v)
#define fe3(a,b,v) for(au&&[a,b]:v)
#define fe4(a,b,c,v) for(au&&[a,b,c]:v)
#define fe5(a,b,c,d,v) for(au&&[a,b,c,d]:v)
#define fe(...) ov5(__VA_ARGS__,fe5,fe4,fe3,fe2)(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;li(__VA_ARGS__)
#define DD(...) dd __VA_ARGS__;li(__VA_ARGS__)
#define CH(...) char __VA_ARGS__;li(__VA_ARGS__)
#define ST(...) str __VA_ARGS__;li(__VA_ARGS__)
#define UL2(n,a) u1 a(n);li(a)
#define UL3(n,a,b) u1 a(n),b(n);li(a,b)
#define UL4(n,a,b,c) u1 a(n),b(n),c(n);li(a,b,c)
#define UL5(n,a,b,c,d) u1 a(n),b(n),c(n),d(n);li(a,b,c,d)
#define UL(...) ov5(__VA_ARGS__,UL5,UL4,UL3,UL2)(__VA_ARGS__)
#define UV3(n,a,b) u1 a(n),b(n);vi(a,b)
#define UV4(n,a,b,c) u1 a(n),b(n),c(n);vi(a,b,c)
#define UV5(n,a,b,c,d) u1 a(n),b(n),c(n),d(n);vi(a,b,c,d)
#define UV(...) ov5(__VA_ARGS__,UV5,UV4,UV3)(__VA_ARGS__)
#define U2(h,w,a) u2 a(h,w);li(a)
#define S2(h,a) strs a(h);li(a)
#define I template
#define J typename
#define O operator
#define rr return
#define uu using
#define au auto
#define cs const
#define th this
#define endl "\n"
namespace atcoder{}namespace my{void main();void solve();}int main(){my::main();}
namespace my{
uu namespace std;uu namespace atcoder;
uu is=istream;uu os=ostream;uu vo=void;uu bo=bool;
uu ll=long long;uu ul=unsigned long long;uu dd=long double;uu i128=__int128_t;
uu ml=modint1000000007;
I<J T>uu v1=vector<T>;
I<J T>struct v2:v1<v1<T>>{uu v1<v1<T>>::v1;v2(ll a,ll b,T x=T{}){th->resize(a,v1<T>(b,x));}};
I<J T>struct v3:v1<v2<T>>{uu v1<v2<T>>::v1;v3(ll a,ll b,ll c,T x=T{}){th->resize(a,v2<T>(b,c,x));}};
I<J T>struct v4:v1<v3<T>>{uu v1<v3<T>>::v1;v4(ll a,ll b,ll c,ll d,T x=T{}){th->resize(a,v3<T>(b,c,d,x));}};
I<J T>struct v5:v1<v4<T>>{uu v1<v4<T>>::v1;v5(ll a,ll b,ll c,ll d,ll e,T x=T{}){th->resize(a,v4<T>(b,c,d,e,x));}};
uu u1=v1<ll>;uu u2=v2<ll>;uu u3=v3<ll>;uu u4=v4<ll>;uu m1=v1<ml>;uu m2=v2<ml>;uu m3=v3<ml>;uu m4=v4<ml>;uu m5=v5<ml>;
uu str=string;uu strs=v1<str>;str sp=" ",nc="",nl="\n";

I<J A,J B=A>struct cp{
  A a;B b;cp():a(A{}),b(B{}){}cp(A a,B b):a(a),b(b){}
  cp O-()cs{rr cp(-a,-b);}
  cp&O+=(cs cp&c){a+=c.a,b+=c.b;rr*th;}cp O+(cs cp&c)cs{rr cp{*th}+=c;}
  cp&O-=(cs cp&c){a-=c.a,b-=c.b;rr*th;}cp O-(cs cp&c)cs{rr cp{*th}-=c;}
  I<J T>cp&O+=(cs T&x){a+=x,b+=x;rr*th;}I<J T>cp O+(cs T&x)cs{rr cp{*th}+=x;}
  I<J T>cp&O-=(cs T&x){a-=x;b-=x;rr*th;}I<J T>cp O-(cs T&x)cs{rr cp{*th}-=x;}
  I<J T>cp&O*=(cs T&x){a*=x;b*=x;rr*th;}I<J T>cp O*(cs T&x)cs{rr cp{*th}*=x;}
  au abs()cs{rr std::abs(a)+std::abs(b);}au abs(cs cp&c)cs{rr(*th-c).abs();}
  bo O==(cs cp&c)cs{rr a==c.a&&b==c.b;}bo O!=(cs cp&c)cs{rr!(*th==c);}
  bo O<(cs cp&c)cs{rr a!=c.a?a<c.a:b<c.b;}bo O>(cs cp&c)cs{rr a!=c.a?a>c.a:b>c.b;}
  friend is&O>>(is&i,cp&c){rr i>>c.a>>c.b;}friend os&O<<(os&o,cs cp&c){rr o<<c.a<<sp<<c.b;}
};uu cl=cp<ll>;uu cls=v1<cl>;
I<J A,J B=A,J C=A>struct tr{
  A a;B b;C c;tr():a(A{}),b(B{}),c(C{}){}tr(A a,B b,C c):a(a),b(b),c(c){}
  bo O==(cs tr&t)cs{rr a==t.a&&b==t.b&&c==t.c;}
  bo O<(cs tr&t)cs{rr a!=t.a?a<t.a:b!=t.b?b<t.b:c<t.c;}bo O>(cs tr&t)cs{rr a!=t.a?a>t.a:b!=t.b?b>t.b:c>t.c;}
  friend is&O>>(is&i,tr&t){rr i>>t.a>>t.b>>t.c;}friend os&O<<(os&o,cs tr&t){rr o<<t.a<<sp<<t.b<<sp<<t.c;}
};uu tl=tr<ll>;uu tls=v1<tl>;
I<J A,J B=A,J C=A,J D=A>struct qu{
  A a;B b;C c;D d;qu():a(A{}),b(B{}),c(C{}),d(D{}){}qu(A a,B b,C c,D d):a(a),b(b),c(c),d(d){}
  bo O==(cs qu&q)cs{rr a==q.a&&b==q.b&&c==q.c&&d==q.d;}
  bo O<(cs qu&q)cs{rr a!=q.a?a<q.a:b!=q.b?b<q.b:c!=q.c?c<q.c:d<q.d;}
  bo O>(cs qu&q)cs{rr a!=q.a?a>q.a:b!=q.b?b>q.b:c!=q.c?c>q.c:d>q.d;}
  friend os&O<<(os&o,cs qu&q){rr o<<q.a<<sp<<q.b<<sp<<q.c<<sp<<q.d;}
};uu ql=qu<ll>;uu qls=v1<ql>;

I<J T>struct set:std::set<T>{set(){}set(cs v1<T>&a){fe(e,a)th->ep(e);}};
I<J T>struct uset:std::unordered_set<T>{uset(){}uset(cs v1<T>&a){fe(e,a)th->ep(e);}};
I<J T>struct mset:multiset<T>{mset(){}mset(cs v1<T>&a){fe(e,a)th->ep(e);}bo erase(cs T&x){bo f=th->count(x);if(f)multiset<T>::erase(th->find(x));rr f;}};
I<J T>uu fn=function<T>;uu mp=map<ll,ll>;uu ump=unordered_map<ll,ll>;uu sl=set<ll>;uu usl=uset<ll>;uu msl=mset<ll>;
I<J T>uu qmax=priority_queue<T>;I<J T>uu qmin=priority_queue<T,v1<T>,greater<T>>;uu dl=deque<ll>;
ll oo=3e18;dd ee=1e-12,pi=acosl(-1);u1 dx{-1,0,1,0,-1,1,1,-1},dy{0,-1,0,1,-1,-1,1,1};
str Yes(bo b=1){rr b?"Yes":"No";}str No(){rr Yes(0);}

bo odd(ll x){rr x&1;}bo eve(ll x){rr !odd(x);}ll pm1(ll x){rr 1-2*(x&1);}ll pw2(ll n){rr 1LL<<n;}
ll rng1(ll l,ll r){rr pw2(r)-pw2(l);}ll rngbit(ll x,ll l,ll r){rr rng1(l,r)&x;}//[l,r)
ll ppc(ll x,ll l=0,ll r=63){rr __builtin_popcountll(rngbit(x,l,r));}
u1 binary(ll x,ll L){u1 r(L);fo(i,L)r[i]=x&1,x>>=1;rr r;}
ll sqr(ll x){if(x<=1)rr x;ll r=sqrtl(x)-1;wh(r+1<=x/(r+1))r++;rr r;}
ll cbr(ll x){if(x<=1)rr x;ll r=cbrtl(x)-1;wh(r+1<=x/(r+1)/(r+1))r++;rr r;}
ll l2(i128 x){if(x<0)rr 0;x|=1;ll r=0;wh(x)x>>=1,r++;rr r;}ll l10(i128 x){if(x<0)rr 0;x|=1;ll r=0;wh(x)x/=10,r++;rr r;}
ll msb(ll x){if(x==0)rr-1;rr l2(x)-1;}ll lsb(ll x){if(x==0)rr-1;rr __builtin_ctzll(x);}
I<J T,J U,J V>au sum(T a,U d,V n){rr n*(a*2+(n-1)*d)/2;}
I<J T>ll len(cs T&a){rr a.size();}I<J T>bo mu(cs T&a){rr !len(a);}
I<J T>T sq(cs T&a){rr a*a;}
I<J T>ll at(T S,ll i){rr S>>i&1;}I<J T>T at(cs v1<T>&v,ll i){ll n=len(v);rr v[(i%n+n)%n];}
I<J T>ll sgn(cs T&a){rr(a>ee)-(a<-ee);}I<J T,J U>ll sgn(cs T&a,cs U&b){rr sgn(a-b);}
I<J T,J U>T cei(T x,U y){assert(y);rr(y<0?cei(-x,-y):(x>0?(x+y-1)/y:x/y));}
I<J T,J U>T flo(T x,U y){assert(y);rr(y<0?flo(-x,-y):(x>0?x/y:x/y-(x%y!=0)));}
ll rp(ll a,ll x=oo,ll y=-1){rr a==x?y:a;}u1 rp(u1 a,ll x=oo,ll y=-1){fo(i,len(a))a[i]=rp(a[i],x,y);rr a;}
I<J T>T rect(cs v1<T>&s,ll l,ll r){assert(0<=l&&l<=r&&r<=len(s));T t{};if(r)t+=s[r-1];if(l)t-=s[l-1];rr t;}
I<J T,J U=T>au as(cs v1<cp<T,U>>&v){v1<T>r;fe(a,b,v)r.eb(a);rr r;}
I<J T,J U=T>au bs(cs v1<cp<T,U>>&v){v1<U>r;fe(a,b,v)r.eb(b);rr r;}

I<J T>au cut(cs v1<T>&a,ll l,ll r){rr v1<T>(al(a,l,r));}
I<J T,J U=T>vo af(v1<T>&v,U e=U{}){v.ep(bgn(v),e);}I<J T>vo df(v1<T>&v){v.erase(bgn(v));}
I<J T>au&bg(T&a){rr*bgn(a);}I<J T>au&bg(cs T&a){rr*bgn(a);}I<J T>au&rb(T&a){rr*rbg(a);}I<J T>au&rb(cs T&a){rr*rbg(a);}
I<J T>T pop(v1<T>&v){T r=rb(v);v.pop_back();rr r;}
I<J T>T pop(qmax<T>&q){T r=q.top();q.pop();rr r;}I<J T>T pop(qmin<T>&q){T r=q.top();q.pop();rr r;}
I<J T>T pof(deque<T>&q){T r=bg(q);q.pop_front();rr r;}I<J T>T pob(deque<T>&q){T r=rb(q);q.pop_back();rr r;}
I<J T>au&O^=(v1<T>&v,cs v1<T>u){copy(al(u),back_inserter(v));rr v;}I<J T>au O^(v1<T>v,cs v1<T>&u){rr v^=u;}
I<J T>au&O+=(v1<T>&v,cs v1<T>&u){fo(i,len(v))v[i]+=u[i];rr v;}I<J T>au O+(v1<T>v,cs v1<T>&u){rr v+=u;}
I<J T>au&O-=(v1<T>&v,cs v1<T>&u){fo(i,len(v))v[i]-=u[i];rr v;}I<J T>au O-(v1<T>v,cs v1<T>&u){rr v-=u;}
I<J T>au O-(v1<T>v){fe(e,v)e=-e;rr v;}
I<J T>au&O++(v1<T>&v){fe(e,v)e++;rr v;}I<J T>au O++(v1<T>&v,int){au r=v;++v;rr r;}
I<J T>au&O--(v1<T>&v){fe(e,v)e--;rr v;}I<J T>au O--(v1<T>&v,int){au r=v;--v;rr r;}
I<J T,J U>au&O+=(v1<T>&v,cs U a){fe(e,v)e+=a;rr v;}I<J T,J U>au O+(v1<T>v,cs U&a){rr v+=a;}
I<J T,J U>au&O-=(v1<T>&v,cs U a){fe(e,v)e-=a;rr v;}I<J T,J U>au O-(v1<T>v,cs U&a){rr v-=a;}
I<J T,J U>au&O*=(v1<T>&v,cs U a){fe(e,v)e*=a;rr v;}I<J T,J U>au O*(v1<T>v,cs U&a){rr v*=a;}
I<J T,J U>au&O/=(v1<T>&v,cs U a){fe(e,v)e/=a;rr v;}I<J T,J U>au O/(v1<T>v,cs U&a){rr v/=a;}
I<J T,J U>bo amax(T&a,cs U&b){rr a<b?a=b,1:0;}I<J T,J U>bo amin(T&a,cs U&b){rr a>b?a=b,1:0;}
I<J T>T max(cs v1<T>&a){rr*max_element(al(a));}I<J T>T min(cs v1<T>&a){rr*min_element(al(a));}
I<J T>au max(cs v2<T>&a){T r=bg(bg(a));fe(v,a)amax(r,max(v));rr r;}
I<J T>au min(cs v2<T>&a){T r=bg(bg(a));fe(v,a)amin(r,min(v));rr r;}
I<J...T>au max(T...a){rr max(initializer_list<common_type_t<T...>>{a...});}
I<J...T>au min(T...a){rr min(initializer_list<common_type_t<T...>>{a...});}
I<J T>ll argmax(cs v1<T>&a){rr max_element(al(a))-bgn(a);}I<J T>ll argmin(cs v1<T>&a){rr min_element(al(a))-bgn(a);}
I<J T>T sum(cs v1<T>&a){rr accumulate(al(a),T{});}I<J T>T sum(cs v2<T>&a){T r{};fe(e,a)r+=sum(e);rr r;}
I<J T>T sum(cs set<T>&s){T r{};fe(e,s)r+=e;rr r;}I<J T>T sum(cs deque<T>&q){T r{};fe(e,q)r+=e;rr r;}
I<J T>T sum(qmax<T>q){T r{};wh(len(q))r+=pop(q);rr r;}I<J T>T sum(qmin<T>q){T r{};wh(len(q))r+=pop(q);rr r;}
I<J T,J U>ll lbs(cs v1<T>&a,cs U&b){rr lb(al(a),b)-bgn(a);}I<J T,J U>ll ubs(cs v1<T>&a,cs U&b){rr ub(al(a),b)-bgn(a);}
I<J T,J U>au minmax(cs T&a,cs U&b){rr cp(min(a,b),max(a,b));}I<J T,J U>au minmax(cs cp<T,U>&p){rr minmax(p.a,p.b);}
u1 io(ll n,ll x=0){u1 a(n);iota(al(a),x);rr a;}

struct fio{fio(){cin.tie(0);ios::sync_with_stdio(0);cout<<fixed<<setprecision(12);}}fio;
is&O>>(is&i,ml&x){ll t;i>>t;x=t;rr i;}os&O<<(os&o,cs ml&x){rr o<<x.val();}
os&O<<(os&o,cs i128&x){if(x<0)rr o<<"-"<<-x;if(x<10)rr o<<(char)(x+'0');rr o<<x/10<<(char)(x%10+'0');}
I<J T,J U>os&O<<(os&o,cs pair<T,U>&p){rr o<<p.first<<sp<<p.second;}
I<J T,J U>os&O<<(os&o,cs map<T,U>&m){fe(p,m)o<<p<<(&p==&rb(m)?nc:nl);rr o;}
I<J T,J U>os&O<<(os&o,cs unordered_map<T,U>&m){fe(p,m)o<<p<<nl;rr o;}
I<J T>os&O<<(os&o,cs set<T>&s){fe(e,s)o<<e<<sp;rr o;}I<J T>os&O<<(os&o,cs mset<T>&s){fe(e,s)o<<e<<sp;rr o;}
I<J T>os&O<<(os&o,cs deque<T>&q){fe(e,q)o<<e<<sp;rr o;}
I<J T>os&O<<(os&o,qmax<T>q){wh(len(q))o<<pop(q)<<sp;rr o;}I<J T>os&O<<(os&o,qmin<T>q){wh(len(q))o<<pop(q)<<sp;rr o;}
I<J T>is&O>>(is&i,v1<T>&v){fe(e,v)i>>e;rr i;}
I<J T>os&O<<(os&o,cs v1<T>&v){fe(e,v)o<<e<<(&e==&rb(v)?nc:sp);rr o;}
I<J T>os&O<<(os&o,cs v2<T>&v){fe(e,v)o<<e<<(&e==&rb(v)?nc:nl);rr o;}
ll pp(){cout<<endl;rr 0;}I<J T,J...A>ll pp(cs T&a,cs A&...b){cout<<a;((cout<<sp<<b),...);rr pp();}
I<J...T>ll li(T&...a){(cin>>...>>a);rr 0;}
I<J...T>vo vi(ll i,T&...a){(cin>>...>>a[i]);}I<J T,J...A>vo vi(v1<T>&a,A&...b){fo(i,len(a))vi(i,a,b...);}
str ins(){ST(r);rr r;}strs ins2(ll n){S2(n,r);rr r;}

struct edg{ll t,w;edg(){}edg(ll t,ll w=1):t(t),w(w){}};uu graph=v2<edg>;
u2 tou(cs graph&g){ll n=len(g);u2 a(n);fo(u,n)fe(v,w,g[u])a[u].eb(v);rr a;}
graph tog(cs u2&a){ll n=len(a);graph g(n);fo(u,n)fe(v,a[u])g[u].eb(v);rr g;}
au mgi(u2&g,ll m){UV(m,a,b);a--,b--;fo(i,m)g[a[i]].eb(b[i]),g[b[i]].eb(a[i]);rr cp(a,b);}
au ygi(u2&g,ll m){UV(m,a,b);a--,b--;fo(i,m)g[a[i]].eb(b[i]);rr cp(a,b);}
au mgi(graph&g,ll m){UV(m,a,b,c);a--,b--;fo(i,m)g[a[i]].eb(b[i],c[i]),g[b[i]].eb(a[i],c[i]);rr tr(a,b,c);}
au ygi(graph&g,ll m){UV(m,a,b,c);a--,b--;fo(i,m)g[a[i]].eb(b[i],c[i]);rr tr(a,b,c);}
au ti(u2&g){rr mgi(g,len(g)-1);}au ti(graph&g){rr mgi(g,len(g)-1);}

str de(cs u1&a,cs char&b='a'){str r{};fe(e,a)r+=e+b;rr r;}
str de(cs u1&a,cs str&b){ll n=len(a);str r(n,'$');fo(i,n)fo(j,len(b))if(a[i]==j){r[i]=b[j];break;}rr r;}
strs de(cs u2&a,cs char&b='a'){ll n=len(a);strs r(n);fo(i,n)r[i]=de(a[i],b);rr r;}
strs de(cs u2&a,cs str&b){ll n=len(a);strs r(n);fo(i,n)r[i]=de(a[i],b);rr r;}
u1 en(cs str&s,cs char&b='a'){u1 r;fe(c,s)r.eb(c-b);rr r;}
u1 en(cs str&s,cs string&b){ll n=len(s);u1 r(n,-1);fo(i,n)fo(j,len(b))if(s[i]==b[j]){r[i]=j;break;}rr r;}
u2 en(cs strs&s,cs char&b='a'){u2 r;fe(e,s)r.eb(en(e,b));rr r;}
u2 en(cs strs&s,cs string&b){u2 r;fe(e,s)r.eb(en(e,b));rr r;}

I<J F>struct rec:private F{explicit rec(F&&f):F(std::forward<F>(f)){}I<J...T>decltype(au)O()(T&&...a)cs{rr F::O()(*th,std::forward<T>(a)...);}};
I<J T,J...A>au tzp(A&...a){v1<T>v;fe(e,{a...})v^=e;uq(v);rr v;}
vo pz(cs u1&v,u1&h){fe(e,h)e=lbs(v,e);}I<J...T>vo pz(cs u1&v,u1&h,T&...t){pz(v,h);pz(v,t...);}
I<J...T>u1 zp(T&...a){u1 v=tzp<ll>(a...);pz(v,a...);rr v;}u1 zp(u2&a){u1 v;fe(e,a)v^=e;uq(v);fe(e,a)fe(x,e)x=lbs(v,x);rr v;}
I<J T>vo sv(cs u1&o,v1<T>&a){au c=a;fo(i,len(a))a[i]=c[o[i]];}I<J T,J...A>vo sv(cs u1&o,v1<T>&a,A&...b){sv(o,a);sv(o,b...);}
I<J T>u1 vs(cs fn<bo(ll,ll)>&f,v1<T>&a){u1 o=io(len(a));sort(al(o),f);sv(o,a);rr o;}
I<J T,J...A>u1 vs(cs fn<bo(ll,ll)>&f,v1<T>&a,A&...b){u1 o=io(len(a));sort(al(o),f);sv(o,a);sv(o,b...);rr o;}

ll bsl(cs fn<bo(ll)>&j,ll o,ll n){wh(abs(o-n)>1)(j((o+n)/2)?o:n)=(o+n)/2;rr o;}
dd bsd(cs fn<bo(dd)>&j,dd o,dd n){wh(abs(o-n)>ee)(j((o+n)/2)?o:n)=(o+n)/2;rr o;}
I<J T>au zt(v1<T>a){fo(i,1,len(a))a[i]+=a[i-1];rr a;}I<J T>au zt(v2<T>a){fe(v,a)v=zt(v);fo(i,1,len(a))a[i]+=a[i-1];rr a;}
I<J T>au mb(v1<T>a){of(i,len(a),1)a[i]-=a[i-1];rr a;}I<J T>au mb(v2<T>a){fe(v,a)v=mb(v);of(i,len(a),1)a[i]-=a[i-1];rr a;}
au rle(cs u1&a){cls r;fe(e,a)len(r)&&e==rb(r).a?rb(r).b++,0:(r.eb(e,1),0);rr r;}
au rce(cs u1&a){cls r;ump m;fe(e,a)m[e]++;fe(k,v,m)r.eb(k,v);rr uq(r),r;}
u1 divs(ll n){u1 r;fo(i,1,n/i+1)if(n%i==0)r.eb(i),r.eb(n/i);rr uq(r),r;}
mp fact(ll n){ump m;fo(i,2,n/i+1)wh(n%i==0)m[i]++,n/=i;if(n>1)m[n]++;rr mp(al(m));}
i128 inv(i128 a,i128 m){a=(a%m+m)%m;i128 b=m,u=1,v=0;wh(b)u-=a/b*v,swap(u,v),a-=a/b*b,swap(a,b);rr(u%m+m)%m;}
i128 pow(i128 x,i128 n){assert(n>=0);i128 r=1;wh(n){if(n&1)r*=x;x*=x,n>>=1;}rr r;}
i128 pow(i128 x,i128 n,i128 m){if(n<0)n=-n,x=inv(x,m);i128 r=1;wh(n){if(n&1)r*=x,r%=m;x*=x,x%=m,n>>=1;}rr r;}
au flo_rng(ll n){tls r;ll m=sqr(n),l=n/(m+1);fo(i,1,m+1)r.eb(n/i,i,i+1);of(i,l+1,1)r.eb(i,n/(i+1)+1,n/i+1);rr r;}//[a,b)

vo main(){ll T=1;fo(T)solve();}
vo solve(){
  LL(N,K);
  if(K<(N+1)/2)fin(-1);
  
  cls res;
  fo(i,0,N-1,2)res.eb(i,i+1);
  fo(K-(N+1)/2)pop(res);
  fo(i,N)res.eb(i,i);
  pp(len(res));
  fe(e,res)pp(e+1);
}}

yukicoder

結果

テストケース

ソースコード