Submission #114201

#	Time	Username	Problem	Language	Result	Execution time	Memory
114201		patrikpavic2	Split the sequence (APIO14_sequence)	C++17	100 / 100	145 ms	9336 KiB

sequence

#include <cstdio>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <algorithm>
#include <algorithm>
#include <deque>

#define X first
#define Y second
#define PB push_back

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair < ll, ll > pll;

const int N = 1e5 + 500;
const int K = 215;

inline bool ccw(const pll &A, const pll &B, const pll &C){
    return (ld)A.X * (B.Y - C.Y) + (ld)B.X * (C.Y - A.Y) + (ld)C.X * (A.Y - B.Y) <= 0;
}

int ind[N], a[N];
pll hl[N];
int cur = 0, n, k;
ll P[N], lst[N], dp[N];
int rek2[N], cur_k, sz, cnt[N], rek[N][K];
ll cost, lo = 0, hi = 1e17;

inline void add_2(const pll &X,const int &i){
    for(;sz >= 2 && ccw(X, hl[sz - 1], hl[sz - 2]); sz--);
    hl[sz] = X; ind[sz++] = i;
    cur = min(cur, sz - 1);
}

inline ll get_2(const int &i,const ll &x){
    return hl[i].X * x + hl[i].Y;
}

inline int query_2(const ll &x){
    if(sz == 0) return -1;
    for(; cur + 1 < sz && get_2(cur, x) < get_2(cur +  1, x); cur++);
    return cur;
}

inline int dinamika_2(){
    sz = 0; cur = 0;
    add_2({0, 0}, 0);
    for(int i = 1;i <= n;i++){
        int r = query_2(P[i]);
        rek2[i] = ind[r];
        cnt[i] = cnt[ind[r]] + 1;
        dp[i] = get_2(r, P[i]) - cost;
        add_2({P[i], dp[i] - P[i] * P[i]}, i);
        //printf("%lld ", dp[i]);
    }
   // printf("\n");
    cur_k++;
    return cnt[n] <= k;
}

inline void add(const pll &X,const int &i){
    for(;sz >= 2 && ccw(X, hl[sz - 1], hl[sz - 2]); sz--);
    hl[sz] = X; ind[sz++] = i;
    cur = min(cur, sz - 1);
}

inline ll get(const int &i,const ll &x){
    return hl[i].X * x + hl[i].Y;
}

inline int query(const ll &x){
    if(sz == 0) return -1;
    for(; cur + 1 < sz && get(cur, x) < get(cur +  1, x); cur++);
    return cur;
}

inline void dinamika(){
    sz = 0; cur = 0;
    for(int i = 0;i < n;i++){
        int r = query(P[i]);
        dp[i] = -1;
        if(r >= 0){
            rek[i][cur_k] = ind[r];
            dp[i] = get(r, P[i]);
        }
        if(lst[i] >= 0)
            add({P[i], lst[i] - P[i] * P[i]}, i);
        lst[i] = dp[i];
    }
    cur_k++;
}

int main(){
    scanf("%d%d", &n, &k);
    if(n > 10000) {

        for(int i = 0;i < n;i++){
            scanf("%d", a + i);
            P[i + 1] = a[i] + P[i];
        }
        //lo = hi = 12;
        cost = (lo + hi) / 2;
        for(int i = 0;i < 60;i++){
            if(dinamika_2()){
                hi = cost;
            }
            else{
                lo = cost;
            }
            cost = (lo + hi) / 2;
            //if(lo  == hi) break;
        }
        printf("%lld\n", dp[n] + (ll)cnt[n] * cost);
        vector < int > fin;
        int cur = n;
        for(int i = 0;i < k;i++){
            cur = rek2[cur];
            fin.PB(cur);
        }
        reverse(fin.begin(), fin.end());
        for(int x : fin)
            printf("%d ", x);
        printf("\n");
    }
    else{
        //if(n > 50000 && k > 150) return 0;
        for(int i = 0;i < n;i++){
            scanf("%d", a + i);
            P[i] = a[i] + (i ? P[i - 1] : 0);
        }
        for(int i = 0;i < k;i++)
            dinamika();
        printf("%lld\n", dp[n - 1]);
        vector < int > fin;
        int cur = n - 1;
        for(int i = k - 1;i >= 0;i--){
            fin.PB(rek[cur][i]);
            cur = fin.back();
        }
        reverse(fin.begin(), fin.end());
        for(int x : fin)
            printf("%d ", x + 1);
        printf("\n");
    }
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:102:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &n, &k);
     ~~~~~^~~~~~~~~~~~~~~~
sequence.cpp:106:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", a + i);
             ~~~~~^~~~~~~~~~~~~
sequence.cpp:136:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", a + i);
             ~~~~~^~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 29 / 29