Submission #601833

#	Time	Username	Problem	Language	Result	Execution time	Memory
601833		MohamedAliSaidane	Roller Coaster Railroad (IOI16_railroad)	C++14	34 / 100	537 ms	40412 KiB

railroad

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include "railroad.h"
        using namespace std;
        using namespace __gnu_pbds;


        ///#define int long long

        typedef tree<int,null_type,less<int>,rb_tree_tag,
        tree_order_statistics_node_update> indexed_set;

        typedef long long ll;

        typedef pair<int,int> pii;
        typedef pair<ll,ll> pll;

        typedef vector<int> vi;
        typedef vector<ll> vll;
        typedef vector<pii> vpi;
        typedef vector<pll> vpl;

        #define ff first
        #define ss second

        #define pb push_back
        #define popb pop_back
        #define all(x) (x).begin(),(x).end()

        const ll INF = 1e18;
        const int nax = 16;
        const int naxx =4e5 + 4;
        int n;
        vll s, t;
        ll dp[(1 << nax)][nax];
        vi adj[naxx];
        vi p, rnk;
        ll f(int mask, int cur)
        {
            //cout <<mask << ' ' << cur << '\n';
            if(mask == (1 << n) - 1)
                return dp[mask][cur] = 0ll;
            if(dp[mask][cur] != -1)
                return dp[mask][cur];
            ll ans = INF;
            for(int i = 0; i < n; i++)
            {
                if((1 << i) & mask)
                    continue;
                ans = min(ans, f(mask + (1 << i), i) + max(0ll,t[cur] - s[i]));
            }
            //cout << cur << ' ' << mask << ' ' << ans << '\n';
            return dp[mask][cur] = ans;
        }
        int findset(int x){return p[x] = p[x] == x? x: findset(p[x]);}
        void unite(int i, int j)
        {
            int x= findset(i);
            int y = findset(j);
            if(x == y)
                return ;
            if(rnk[x] > rnk[y])
                swap(x,y);
            p[x]=  y;
            if(rnk[x] == rnk[y])
                rnk[y]++;
        }
        ll plan_roller_coaster( vi S, vi T)
        {
            int N = S.size();
            n = N;
            for(int i = 0; i < n; i ++)
                t.pb(T[i]);
            for(int i = 0; i < n; i ++)
                s.pb(S[i]);
            if(n <= 16)
            {
                ll ans = INF;
                memset(dp,-1,sizeof(dp));
                for(int i=  0 ; i < n; i++)
                {
                    ans  = min(ans, f(( 1<< i), i));
                }
                return ans;
            }
            indexed_set nid;
            nid.insert(1);
            nid.insert(1e9);
            for(int i = 0; i < n; i++)
            {
                nid.insert(s[i]);
                nid.insert(t[i]);
            }
            int sz = nid.size();
            p.assign(sz, 0);
            rnk.assign(sz,0);
            for(int i=  0 ; i < n;i ++)
                p[i] = i;

            int suf[sz + 1];
            memset(suf,0,sizeof(suf));
            int u =nid.order_of_key(1);
            int v = nid.order_of_key(1e9);
            unite(u,v);
            suf[u] += 1;
            suf[v] -= 1;
            for(int i= 0; i < n; i++)
            {
                u = nid.order_of_key(s[i]);
                v = nid.order_of_key(t[i]);
                suf[u] += 1;
                suf[v] -= 1;
                unite(u,v);
            }
            int cur = 0;
            for(int i =  0;i < sz - 1; i ++)
            {
                cur += suf[i];
                if(cur > 0)
                    return 2;
                if(cur == 0 )
                unite(i, i + 1);
            }
            for(int i = 1; i < sz; i ++)
                if(findset(i) != findset(0))
                    return 1;
            return 0  ;
        }
        /*
        int main()
        {
            int n;
            assert(1 == scanf("%d", &n));
            std::vector<int> s(n), t(n);
            for (int i = 0; i < n; ++i)
                assert(2 == scanf("%d%d", &s[i], &t[i]));
            long long ans = plan_roller_coaster(s, t);
            printf("%lld\n", ans);
            return 0;
        }
        */

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 0 / 30
• Subtask 4: 0 / 36