Submission #918624

#	Time	Username	Problem	Language	Result	Execution time	Memory
918624		Boycl07	Split the sequence (APIO14_sequence)	C++17	71 / 100	79 ms	131072 KiB

sequence

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define rep(i, n) for(int i = 1; i <= n; ++i)
#define forn(i, l, r) for(int i = l; i <= r; ++i)
#define ford(i, r, l) for(int i = r; i >= l; --i)
#define FOR(i, n) for(int i = 0; i < n; ++i)
#define fi first
#define se second
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define endl "\n"
#define task "split"
#define sz(a) int(a.size())
#define C(x, y) make_pair(x, y)
#define all(a) (a).begin(), (a).end()
#define bit(i, mask) (mask >> i & 1)

template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }

inline int readInt()       {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();int n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline ll readLong()       {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();ll  n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline string readString() {char c;while(c=getchar(),c==' '||c=='\n'||c=='\t');string s({c});while(c=getchar(),c!=EOF&&c!=' '&&c!='\n'&&c!='\t')s+=c;return s;}


const int N = 5e5 + 4;
const int M = 3e5 + 3;
const int INF = 1e9 + 3;
const ll LINF = 1e18;
const int A = 26 + 2;
const int K = 200 + 3;

int n, k;

int a[N];

int sum[N];

ll dp[N][K];

int opt[N][K];

ll cost(int i, int j)
{
    return 1ll * (sum[i - 1]) * (sum[j] - sum[i - 1]);
}

int j = 0;

void dnc(int l, int r, int optl, int optr)
{
    if(l > r) return;
    int mid = l + r >> 1;

    opt[mid][j] = optl;
    forn(k, optl, min(optr, mid))
        if(maximize(dp[mid][j], dp[k - 1][j - 1] + cost(k, mid)))
            opt[mid][j] = k;
    dnc(l, mid - 1, optl, opt[mid][j]);
    dnc(mid + 1, r, opt[mid][j], optr);
}



void solve()
{
    cin >> n >> k;
    rep(i, n) cin >> a[i], sum[i] = sum[i - 1] + a[i];
    dp[0][0] = 0;
    rep(i, n) dp[i][0] = -LINF;
    rep(_, k + 1)
    {
        ++j;
        forn(i, 0, n) dp[i][j] = -LINF;
        dnc(1, n, 1, n);
    }
    cout << dp[n][k + 1] << endl;
    int x = n;
    ford(i, k, 1)
    {
        x = opt[x][i + 1] - 1;
        cout << x << " ";
    }
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int TC = 1;

    if(fopen(task".inp", "r"))
    {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }


    while(TC--)
    {
        solve();
        cout << endl;
    }

    return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'void dnc(int, int, int, int)':
sequence.cpp:58:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   58 |     int mid = l + r >> 1;
      |               ~~^~~
sequence.cpp: In function 'int main()':
sequence.cpp:100:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sequence.cpp:101:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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