CSES - Datatähti Open 2021 - Results
Submission details
Task:Programmers
Sender:rivalq
Submission time:2021-01-31 12:45:50 +0200
Language:C++11
Status:READY
Result:34
Feedback
groupverdictscore
#1ACCEPTED34
#20
#30
Test results
testverdicttimegroup
#1ACCEPTED0.01 s1, 2, 3details
#2ACCEPTED0.01 s1, 2, 3details
#3ACCEPTED0.01 s1, 2, 3details
#4ACCEPTED0.01 s1, 2, 3details
#5ACCEPTED0.01 s1, 2, 3details
#6ACCEPTED0.01 s1, 2, 3details
#7ACCEPTED0.01 s1, 2, 3details
#8ACCEPTED0.01 s1, 2, 3details
#9ACCEPTED0.02 s1, 2, 3details
#10ACCEPTED0.05 s1, 2, 3details
#11ACCEPTED0.01 s1, 2, 3details
#12ACCEPTED0.01 s1, 3details
#13ACCEPTED0.01 s1, 3details
#14ACCEPTED0.01 s1, 3details
#15ACCEPTED0.01 s1, 3details
#16ACCEPTED0.04 s1, 3details
#17ACCEPTED0.28 s2, 3details
#18ACCEPTED0.70 s2, 3details
#19ACCEPTED0.81 s2, 3details
#20--2, 3details
#21--2, 3details
#22--2, 3details
#23--2, 3details
#24--3details
#25--3details
#26--3details
#27--3details
#28--3details
#29--3details
#30--3details
#31--3details

Code

// Jai Shree Ram  
  
#include<bits/stdc++.h>
using namespace std;

#define rep(i,a,n)     for(int i=a;i<n;i++)
#define ll             long long
#define int            long long
#define pb             push_back
#define all(v)         v.begin(),v.end()
#define endl           "\n"
#define x              first
#define y              second
#define gcd(a,b)       __gcd(a,b)
#define mem1(a)        memset(a,-1,sizeof(a))
#define mem0(a)        memset(a,0,sizeof(a))
#define sz(a)          (int)a.size()
#define pii            pair<int,int>
#define hell           1000000007
#define elasped_time   1.0 * clock() / CLOCKS_PER_SEC



template<typename T1,typename T2>istream& operator>>(istream& in,pair<T1,T2> &a){in>>a.x>>a.y;return in;}
template<typename T1,typename T2>ostream& operator<<(ostream& out,pair<T1,T2> a){out<<a.x<<" "<<a.y;return out;}
template<typename T,typename T1>T maxs(T &a,T1 b){if(b>a)a=b;return a;}
template<typename T,typename T1>T mins(T &a,T1 b){if(b<a)a=b;return a;}

template<typename flow_t =int, typename cost_t =int>
struct mcSFlow{
    struct Edge{
        cost_t c;
        flow_t f;
        int to, rev;
        Edge(int _to, cost_t _c, flow_t _f, int _rev):c(_c), f(_f), to(_to), rev(_rev){}
    };
    const cost_t INFCOST = numeric_limits<cost_t>::max()/4;
    const cost_t INFFLOW = numeric_limits<flow_t>::max()/4;
    cost_t epsilon;
    int N, S, T;
    vector<vector<Edge> > G;
    vector<unsigned int> isEnqueued, state;
    mcSFlow(int _N, int _S, int _T):epsilon(0), N(_N), S(_S), T(_T), G(_N){}
    void add_edge(int a, int b, flow_t cap, cost_t cost){
        if(a==b){assert(cost>=0); return;}
        cost*=N;// to preserve integer-values
        epsilon = max(epsilon, abs(cost));
        assert(a>=0&&a<N&&b>=0&&b<N);
        G[a].emplace_back(b, cost, cap, G[b].size());
        G[b].emplace_back(a, -cost, 0, G[a].size()-1);
    }
    flow_t calc_max_flow(){ // Dinic max-flow
        vector<flow_t> dist(N), state(N);
        vector<Edge*> path(N);
        auto cmp = [](Edge*a, Edge*b){return a->f < b->f;};
        flow_t addFlow, retflow=0;;
        do{
            fill(dist.begin(), dist.end(), -1);
            dist[S]=0;
            auto head = state.begin(), tail = state.begin();
            for(*tail++ = S;head!=tail;++head){
                for(Edge const&e:G[*head]){
                    if(e.f && dist[e.to]==-1){
                        dist[e.to] = dist[*head]+1;
                        *tail++=e.to;
                    }
                }
            }
            addFlow = 0;
            fill(state.begin(), state.end(), 0);
            auto top = path.begin();
            Edge dummy(S, 0, INFFLOW, -1);
            *top++ = &dummy;
            while(top != path.begin()){
                int n = (*prev(top))->to;
                if(n==T){
                    auto next_top = min_element(path.begin(), top, cmp);
                    flow_t flow = (*next_top)->f;
                    while(--top!=path.begin()){
                        Edge &e=**top, &f=G[e.to][e.rev];
                        e.f-=flow;
                        f.f+=flow;
                    }
                    addFlow=1;
                    retflow+=flow;
                    top = next_top;
                    continue;
                }
                for(flow_t &i=state[n], i_max = G[n].size(), need = dist[n]+1;;++i){
                    if(i==i_max){
                        dist[n]=-1;
                        --top;
                        break;
                    }
                    if(dist[G[n][i].to] == need && G[n][i].f){
                        *top++ = &G[n][i];
                        break;
                    }
                }
            }
        }while(addFlow);
        return retflow;
    }
    vector<flow_t> excess;
    vector<cost_t> h;
    void push(Edge &e, flow_t amt){
        if(e.f < amt) amt=e.f;
        e.f-=amt;
        excess[e.to]+=amt;
        G[e.to][e.rev].f+=amt;
        excess[G[e.to][e.rev].to]-=amt;
    }
    void relabel(int vertex){
        cost_t newHeight = -INFCOST;
        for(unsigned int i=0;i<G[vertex].size();++i){
            Edge const&e = G[vertex][i];
            if(e.f && newHeight < h[e.to]-e.c){
                newHeight = h[e.to] - e.c;
                state[vertex] = i;
            }
        }
        h[vertex] = newHeight - epsilon;
    }
    const int scale=2;
    pair<flow_t, cost_t> minCostFlow(){
        cost_t retCost = 0;
        for(int i=0;i<N;++i){
            for(Edge &e:G[i]){
                retCost += e.c*(e.f);
            }
        }
        //find feasible flow
        flow_t retFlow = calc_max_flow();
        excess.resize(N);h.resize(N);
        queue<int> q;
        isEnqueued.assign(N, 0); state.assign(N,0);
        // cost scaling
        for(;epsilon;epsilon>>=scale){
            fill(state.begin(), state.end(), 0);
            for(int i=0;i<N;++i)
                for(auto &e:G[i])
                    if(h[i] + e.c - h[e.to] < 0 && e.f) push(e, e.f);
            for(int i=0;i<N;++i){
                if(excess[i]>0){
                    q.push(i);
                    isEnqueued[i]=1;
                }
            }
            while(!q.empty()){
                int cur=q.front();q.pop();
                isEnqueued[cur]=0;
                // discharge
                while(excess[cur]>0){
                    if(state[cur] == G[cur].size()){
                        relabel(cur);
                    }
                    for(unsigned int &i=state[cur], max_i = G[cur].size();i<max_i;++i){
                        Edge &e=G[cur][i];
                        if(h[cur] + e.c - h[e.to] < 0){
                            push(e, excess[cur]);
                            if(excess[e.to]>0 && isEnqueued[e.to]==0){
                                q.push(e.to);
                                isEnqueued[e.to]=1;
                            }
                            if(excess[cur]==0) break;
                        }
                    }
                }
            }
            if(epsilon>1 && epsilon>>scale==0){
                epsilon = 1<<scale;
            }
        }
        for(int i=0;i<N;++i){
            for(Edge &e:G[i]){
                retCost -= e.c*(e.f);
            }
        }
        return make_pair(retFlow, retCost/2/N);
    }
    flow_t getFlow(Edge const &e){
        return G[e.to][e.rev].f;
    }
};
// pass edges in the form ... from to capacity cost
 
// constructor in the form indexOfLastVertex+1,source,sink
 


int solve(){
 		int n,k;cin>>n>>k;
 		int s1=n+1,s=n+2,t=n+3;
 		mcSFlow<int,int> ms(t+1,s1,t);
 		vector<int>a(n+1);
 		ms.add_edge(s1,s,k,0);
 		rep(i,1,n+1){
 			cin>>a[i];
 			if(i%2==0){
 				ms.add_edge(i,t,1,0);
 			}
 			else{
 				ms.add_edge(s,i,1,0);
 			}
 		}
 		sort(a.begin()+1,a.end());
 		for(int i=1;i<=n;i+=2){
 			if(i>0){
 				ms.add_edge(i,i-1,1,a[i]-a[i-1]);
 			}			
 			if(i+1<=n){
 				ms.add_edge(i,i+1,1,a[i+1]-a[i]);
 			}
 		}	
 		cout<<ms.minCostFlow().y<<endl;
 return 0;
}
signed main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    #ifdef SIEVE
    sieve();
    #endif
    #ifdef NCR
    init();
    #endif
    int t=1;//cin>>t;
    while(t--){
        solve();
    }
    return 0;
}
 

Test details

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

input
8 3
3 1 2 7 9 3 4 7

correct output
1

user output
1

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

input
2 1
2 13

correct output
11

user output
11

Test 3

Group: 1, 2, 3

Verdict: ACCEPTED

input
20 10
16 20 6 15 19 12 11 17 20 6 15...

correct output
6

user output
6

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

input
14 5
11 3 8 3 14 8 10 13 11 10 17 1...

correct output
0

user output
0

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED

input
15 1
8 5 1 8 18 15 6 20 14 9 10 9 1...

correct output
0

user output
0

Test 6

Group: 1, 2, 3

Verdict: ACCEPTED

input
10 3
10 19 16 15 12 5 14 8 3 15

correct output
4

user output
4

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

input
202 90
177 187 183 647 616 580 499 78...

correct output
213

user output
213

Test 8

Group: 1, 2, 3

Verdict: ACCEPTED

input
2000 512
141 583 135 833 900 308 248 58...

correct output
0

user output
0

Test 9

Group: 1, 2, 3

Verdict: ACCEPTED

input
2000 972
685 4 289 865 93 159 48 866 56...

correct output
276

user output
276

Test 10

Group: 1, 2, 3

Verdict: ACCEPTED

input
2000 1000
698 153 298 118 631 341 238 7 ...

correct output
517

user output
517

Test 11

Group: 1, 2, 3

Verdict: ACCEPTED

input
2000 1
983 144 449 584 839 166 77 885...

correct output
0

user output
0

Test 12

Group: 1, 3

Verdict: ACCEPTED

input
1464 320
846762124 954854396 12767390 7...

correct output
35809369

user output
35809369

Test 13

Group: 1, 3

Verdict: ACCEPTED

input
2000 231
801945178 924940258 369188694 ...

correct output
7831421

user output
7831421

Test 14

Group: 1, 3

Verdict: ACCEPTED

input
2000 461
464790475 932031556 838378103 ...

correct output
37272564

user output
37272564

Test 15

Group: 1, 3

Verdict: ACCEPTED

input
2000 100
484046702 267135814 995006323 ...

correct output
1268400

user output
1268400

Test 16

Group: 1, 3

Verdict: ACCEPTED

input
2000 996
98352148 438929491 242618159 1...

correct output
445965905

user output
445965905

Test 17

Group: 2, 3

Verdict: ACCEPTED

input
65879 19675
896 316 972 476 636 227 716 78...

correct output
0

user output
0

Test 18

Group: 2, 3

Verdict: ACCEPTED

input
200000 53820
995 720 135 767 943 742 191 26...

correct output
0

user output
0

Test 19

Group: 2, 3

Verdict: ACCEPTED

input
200000 32297
527 947 84 851 908 833 339 112...

correct output
0

user output
0

Test 20

Group: 2, 3

Verdict:

input
200000 99982
561 174 242 275 460 109 664 68...

correct output
322

user output
(empty)

Test 21

Group: 2, 3

Verdict:

input
200000 99955
911 33 314 861 298 117 972 982...

correct output
245

user output
(empty)

Test 22

Group: 2, 3

Verdict:

input
200000 99972
783 1000 673 611 87 452 702 92...

correct output
290

user output
(empty)

Test 23

Group: 2, 3

Verdict:

input
200000 99961
795 136 128 643 60 422 371 839...

correct output
252

user output
(empty)

Test 24

Group: 3

Verdict:

input
195426 76599
442872072 619088799 118541378 ...

correct output
143376538

user output
(empty)

Test 25

Group: 3

Verdict:

input
200000 1661
894106972 620084612 931442312 ...

correct output
33089

user output
(empty)

Test 26

Group: 3

Verdict:

input
200000 86032
211444153 846442677 297198384 ...

correct output
196001810

user output
(empty)

Test 27

Group: 3

Verdict:

input
200000 28275
28280312 349705372 96535649 84...

correct output
11627219

user output
(empty)

Test 28

Group: 3

Verdict:

input
200000 81473
178022892 112774306 250584651 ...

correct output
162430841

user output
(empty)

Test 29

Group: 3

Verdict:

input
200000 99987
297598052 494409138 182268523 ...

correct output
489497036

user output
(empty)

Test 30

Group: 3

Verdict:

input
200000 99971
316462272 843156468 434342923 ...

correct output
483167476

user output
(empty)

Test 31

Group: 3

Verdict:

input
200000 99964
811543559 465033274 620180191 ...

correct output
481497328

user output
(empty)