Submission #46314

#	Time	Username	Problem	Language	Result	Execution time	Memory
46314		RayaBurong25_1	Split the sequence (APIO14_sequence)	C++14	71 / 100	2060 ms	87036 KiB

sequence

#include <stdio.h>
#include <vector>
#include <algorithm>
#include <cassert>
#define INF 1e18
long long Sum[100005];
long long SumSq[100005];
long long DP[100005][2];
int Last[100005][205];
typedef struct line line;
struct line
{
    long long m, c;
    double s;
    int i;
};
line Lines[100005];
int L;
long long max(long long a, long long b)
{
    return (a > b)?a:b;
}
int compare(long long x, line l)
{
    return x < l.s;
}
int I, J;
double intersect(long long m, long long c, long long m2, long long c2)
{
    if (m == m2)
    {
        if (c2 >= c)
            return -INF;
        else
            return INF;
    }
    else
        return (double) (c2 - c)/(m - m2);
}
int main()
{
    int N, K;
    scanf("%d %d", &N, &K);
    int n, k, i;
    for (i = 0; i < N; i++)
    {
        scanf("%lld", &Sum[i]);
        if (i > 0)
            Sum[i] += Sum[i - 1];
        SumSq[i] = Sum[i]*Sum[i];
    }
    long long r, c;
    double s;
    for (k = 1; k <= K; k++)
    {
        L = 1;
        J = 0;
        Lines[0] = {0, 0, -INF, -1};
        for (n = 0; n < N; n++)
        {
            while (J + 1 < L && Lines[J + 1].s <= Sum[n])
                J++;
            DP[n][k%2] = Lines[J].m*Sum[n] + Lines[J].c;
            Last[n][k] = Lines[J].i;

            c = DP[n][(k - 1)%2] - SumSq[n];
            while (L > 0 && (s = intersect(Lines[L - 1].m, Lines[L - 1].c, Sum[n], c)) <= Lines[L - 1].s)
                L--;
            if (s != INF)
            {
                Lines[L] = {Sum[n], c, s, n};
                L++;
            }
        }
        // printf("k%d\n", k);
    }
    printf("%lld\n", DP[N - 1][K%2]);
    i = Last[N - 1][K];
    k = K - 1;
    std::vector<int> V;
    while (k >= 0 && i != -1)
    {
        V.push_back(i + 1);
        i = Last[i][k];
        k--;
    }
    for (i = V.size() - 1; i >= 0; i--)
        printf("%d ", V[i]);
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:52:15: warning: unused variable 'r' [-Wunused-variable]
     long long r, c;
               ^
sequence.cpp:43:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &N, &K);
     ~~~~~^~~~~~~~~~~~~~~~~
sequence.cpp:47:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld", &Sum[i]);
         ~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 0 / 29