Submission #1115257

#	Time	Username	Problem	Language	Result	Execution time	Memory
1115257		gdragon	Split the sequence (APIO14_sequence)	C++17	100 / 100	1224 ms	82116 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
#define TASK "long"
#define fi first
#define se second
#define ll long long
#define pb push_back
#define ALL(x) (x).begin(), (x).end()
#define GETBIT(mask, i) ((mask) >> (i) & 1)
#define MASK(i) ((1LL) << (i))
#define SZ(x) ((int)(x).size())
#define mp make_pair
#define CNTBIT(mask) __builtin_popcount(mask)
template<class X, class Y> bool maximize(X &x, Y y){ if (x < y) {x = y; return true;} return false;};
template<class X, class Y> bool minimize(X &x, Y y){ if (x > y) {x = y; return true;} return false;};
typedef pair<int, int> ii;
const int N = 1e5 + 5;
const int INF = 1e9 + 7;
const int mod = 1e9 + 7;
long long dp[2][N], f[N];
int trace[205][N];
int n, k;
int a[N];
void read() {
    cin >> n >> k;
    for(int i = 1; i <= n; i++) cin >> a[i];
}
long long sum(int l, int r) {
    if (l > r) return 0;
    return f[r] - f[l - 1];
}
long long cost(int l, int r) {
    return -(1LL * sum(l, r) * sum(r + 1, n));
}
void calDp(int g, int l, int r, int optl, int optr) {
    if (l > r) return;
    int best = optl;
    int mid = (l + r) >> 1;
    for(int i = optl; i <= min(mid, optr); i++) {
        if (minimize(dp[(g & 1)][mid], dp[(g & 1) ^ 1][i - 1] + cost(i, mid))) {
            trace[g][mid] = i - 1;
            // cerr << g << ' ' << mid << ' ' << -dp[g][mid] << endl;
            best = i;
        }
    }
    calDp(g, l, mid - 1, optl, best);
    calDp(g, mid + 1, r, best, optr);
}
void solve() {
    for(int i = 1; i <= n; i++) f[i] = f[i - 1] + a[i];
    memset(dp, 0x3f, sizeof(dp));
    dp[0][0] = 0;
    ++k;
    for(int i = 1; i <= k; i++) {
        memset(dp[i & 1], 0x3f, sizeof(dp[i & 1]));
        calDp(i, 1, n, 1, n);
    }
    cout << -dp[k & 1][n] << endl;
    int j = k, i = n;
    vector<int> c;
    while(i) {
        i = trace[j][i];
        if (i == 0) break;
        c.push_back(i);
        --j;
    }
    reverse(ALL(c));
    for(int &x: c) cout << x << ' ';
}
signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
    int test = 1;
    // cin >> test;
    while(test--) {
        read();
        solve();
    }
    return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:73:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sequence.cpp:74:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |         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: 29 / 29