제출 #1254982

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1254982		hoa208	수열 (APIO14_sequence)	C++20	100 / 100	573 ms	85624 KiB

sequence

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, b, a) for (int i = (b), _a = (a); i >= _a; i--)
#define pa pair<ll, ll>
#define fi first
#define se second
#define bit(mask, j) ((mask >> j) & 1)
#define t_test int t;cin >> t;while(t--)
const   ll mod = 1e9 + 7;
const   ll INF = 1e14;
inline  void adm(ll &x){if(x>=mod)x%=mod;else if(x<0)x+=mod;}
//--------------------------------------------------------------------
const ll N = 1e5 + 1;
ll s[N];
ll dp[N], dp2[N];
int trace[N][203];
vector<pa> vt;
vector<ll> vtid;
bool bad(pa &x, pa &y, pa &z) {
   return (y.se - x.se) * (x.fi - z.fi) >= (z.se - x.se) * (x.fi - y.fi);
}
void add(ll a, ll b, ll id) {
    pa p = {a, b};
    while(vt.size() >= 2 && bad(vt[vt.size() - 2], vt[vt.size() - 1], p)) {
        vt.pop_back();
        vtid.pop_back();
    }
    vt.push_back(p);
    vtid.push_back(id);
}
ll f(pa line, ll x) {
    return x * line.fi + line.se;
}
ll pos = 0;
pa query(ll x) {
    if(vt.size() == 0) {
        return {-INF, 0};
    }
    if(pos >= vt.size()) {
        pos = vt.size() - 1;
    }
    while (pos < (ll) (vt.size() - 1) && f(vt[pos + 1], x) > f(vt[pos], x))
        pos++;
    return {f(vt[pos], x), vtid[pos]};
    // ll l = 0, r = (ll)vt.size() - 1;
    // if (r < l) return { -INF, 0 };


    // ll res = -INF, id = 0;
    // ll pre = -1;
    // FOR(i, l, r) {
    //     auto val = f(vt[i], x);
    //     // if(i + 1 <= r && f(vt[i], x) <= f(vt[i + 1], x)) {
    //     //     if(pre != -1 && pre != i - 1) {
    //     //         ll c = 0;
    //     //         for(auto e : vt) {
    //     //             c++;
    //     //             cout << f(e, x) << ' ' << c<< '\n';
    //     //         }
    //     //         exit(0);
    //     //     }pre = i;
    //     //     // if(val == 2016037) {
    //     //     //     for(auto e : vt) {
    //     //     //         cout << f(e, x) << '\n';
    //     //     //     }
    //     //     //     exit(0);
    //     //     // }
    //     // }
    //     if (res < val) {
    //         res = val;
    //         id = vtid[i];
    //     }
    // }
    // return {res, id};
}
void hbmt() {
    ll n, k;
    cin >> n >> k;
    FOR(i, 1, n) {
        ll x;
        cin >> x;
        s[i] = s[i - 1] + x;
    }
    FOR(i, 1, n) {
        dp[i] = -INF;
    }
    FOR(i, 0, n) {
        dp2[i] = -INF;
    }
    dp[0] = 0;
    k++;
    FOR(j, 1, k) {
        pos = 0;
        if(dp[0] > -INF)
            add(s[0], dp[0], 0);
        FOR(i, 1, n) {
            pa cur = query(s[i]);
            dp2[i] = cur.fi;
            trace[i][j] = cur.se;
            if(dp[i] > -INF)
                add(s[i], dp[i] - s[i] * s[i], i);
        }
        FOR(i, 0, n) {
            dp[i] = dp2[i];
            dp2[i] = -INF;
        }
        vt.clear();
        vtid.clear();
    }
    int e = trace[n][k--];
    vector<ll> vt;
    while(e != 0) {
        vt.push_back(e);
        e = trace[e][k--];
    }
    reverse(vt.begin(), vt.end());
    cout << dp[n] << '\n';
    for(auto e : vt) {
        cout << e << ' ';
    }
}

int main() {
    
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    
    if(fopen("hbmt.inp", "r")) {
        freopen("hbmt.inp", "r", stdin);
        freopen("hbmt.out", "w", stdout);
    }
    
    // t_test 
    hbmt();
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

sequence.cpp: In function 'int main()':
sequence.cpp:131:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  131 |         freopen("hbmt.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
sequence.cpp:132:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  132 |         freopen("hbmt.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