Submission #971034

#	Time	Username	Problem	Language	Result	Execution time	Memory
971034		aryanc403	Finding Routers (IOI20_routers)	C++17	100 / 100	5 ms	860 KiB

routers

/*
  Compete against Yourself.
  Author - Aryan (@aryanc403)
*/
/*
  Credits -
  Atcoder library - https://atcoder.github.io/ac-library/production/document_en/ (namespace atcoder)
  Github source code of library - https://github.com/atcoder/ac-library/tree/master/atcoder
  https://codeforces.com/contest/4/submission/150120627
*/
#include "routers.h"

#ifdef ARYANC403
    #include <header.h>
#else
    #pragma GCC optimize ("Ofast")
    #pragma GCC target ("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx")
    // #pragma GCC target ("sse,sse2,mmx")
    #pragma GCC optimize ("-ffloat-store")
    #include <bits/stdc++.h>
    #include <ext/pb_ds/assoc_container.hpp>
    #include <ext/pb_ds/tree_policy.hpp>
    #define dbg(args...) 42;
    #define endl "\n"
#endif

// y_combinator from @neal template https://codeforces.com/contest/1553/submission/123849801
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0200r0.html
template<class Fun> class y_combinator_result {
    Fun fun_;
public:
    template<class T> explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {}
    template<class ...Args> decltype(auto) operator()(Args &&...args) { return fun_(std::ref(*this), std::forward<Args>(args)...); }
};
template<class Fun> decltype(auto) y_combinator(Fun &&fun) { return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun)); }

using namespace std;
#define fo(i,n)   for(i=0;i<(n);++i)
#define repA(i,j,n)   for(i=(j);i<=(n);++i)
#define repD(i,j,n)   for(i=(j);i>=(n);--i)
#define all(x) begin(x), end(x)
#define sz(x) ((lli)(x).size())
#define eb emplace_back
#define X first
#define Y second

using lli = long long int;
using mytype = long double;
using ii = pair<lli,lli>;
using vii = vector<ii>;
using vi = vector<lli>;

template <class T>
using ordered_set =  __gnu_pbds::tree<T,__gnu_pbds::null_type,less<T>,__gnu_pbds::rb_tree_tag,__gnu_pbds::tree_order_statistics_node_update>;


std::vector<int> find_routers(int l, int n, int q) {

    std::vector<int> ans(n);

    map<lli,lli> dp;
    auto getVal=[&](const lli L)->lli{
        if(dp.count(L))
            return dp[L];
        auto it=dp.lower_bound(L);
        auto jt=it;
        if(jt!=dp.begin()&&it!=dp.end()){
            --jt;
            if(jt->Y==it->Y)
                return it->Y;
        }
        const lli h = use_detector(L);
        return dp[L]=h;
    };

    y_combinator([&](const auto &self,const lli l,const lli r)->void{
    	if(getVal(l)==getVal(r))
            return;
        if(r-l<2)
            return;
        const lli m=(l+r)/2;
        self(l,m);
        self(m,r);
    })(0,l);
    dbg(dp);

    std::vector<lli> mids(n,l);
    for(const auto &x:dp)
    	mids[x.Y]=min(mids[x.Y],x.X);

    for (int i = 1; i < n; i++) {
        const int mid = mids[i]-1;
        ans[i]=2*mid-ans[i-1];
    }
    return ans;
}

Compilation message (stderr)

routers.cpp: In function 'std::vector<int> find_routers(int, int, int)':
routers.cpp:23:26: warning: statement has no effect [-Wunused-value]
   23 |     #define dbg(args...) 42;
      |                          ^~
routers.cpp:85:5: note: in expansion of macro 'dbg'
   85 |     dbg(dp);
      |     ^~~

• Subtask 1: 16 / 16
• Subtask 2: 21 / 21
• Subtask 3: 23 / 23
• Subtask 4: 40 / 40