제출 #701692

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
701692		Asamai	Bigger segments (IZhO19_segments)	C++17	37 / 100	135 ms	46672 KiB

segments

#include <bits/stdc++.h>

using namespace std;

template<class A, class B> bool maximize(A& x, B y) {if (x < y) return x = y, true; else return false;}
template<class A, class B> bool minimize(A& x, B y) {if (x > y) return x = y, true; else return false;}

void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << " ]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#define     deb(x...)             cerr << "[ in " <<__func__<< "() : line " <<__LINE__<< " ] : [ " << #x << " ] = [ "; _print(x); cerr << '\n';

typedef     long long             ll;
typedef     unsigned long long    ull;
typedef     double                db;
typedef     long double           ld;
typedef     pair<db, db>          pdb;
typedef     pair<ld, ld>          pld;
typedef     pair<int, int>        pii;
typedef     pair<ll, ll>          pll;
typedef     pair<ll, int>         plli;
typedef     pair<int, ll>         pill;

#define     all(a)                a.begin(), a.end()
#define     pb                    push_back
#define     pf                    push_front
#define     fi                    first
#define     se                    second
#define     int                   long long

const int MAX_N = 5e5 + 5;
const int MAX_M = 3000 + 5;
const int inf = 1e18 + 1;

int n;
int a[MAX_N];
int sum[MAX_N];
pii dp[MAX_N];
int dp2[MAX_M][MAX_M];

void update(pii &a, const pii& b) {
    if (a.fi == b.fi) {
        minimize(a.se, b.se);
    }
    else {
        if (b.fi > a.fi) {
            a = b;
        }
    }
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> n;

    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        sum[i] = sum[i - 1] + a[i];
        dp[i] = {1, sum[i]};
    }

    if (n <= 3000) {
         for (int i = 1; i <= n; i++) {
            dp2[i][1] = 1;
        }

        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= i; j++) {
                maximize(dp2[i][j], dp2[i - 1][j]);
                if (!dp2[i][j] || i == n) continue;
                int curr = sum[i] - sum[j - 1];
                int low = i + 1, high = n;
                int res = n + 1;
                while (low <= high) {
                    int mid = (low + high) >> 1;
                    if (sum[mid] - sum[i] >= curr) {
                        res = mid;
                        high = mid - 1;
                    }
                    else {
                        low = mid + 1;
                    }
                }
                if (res <= n) {
                    maximize(dp2[res][i + 1], dp2[i][j] + 1);
                }
            }
        }

        int ans = 1;
        for (int i = 1; i <= n; i++) {
            maximize(ans, dp2[n][i]);
        }

        cout << ans;
        return 0;
    }

    for (int i = 1; i <= n; i++) {
         update(dp[i], {dp[i - 1].fi, dp[i - 1].se + a[i]});
        int low = i + 1, high = n;
        int k = n + 1;
        while (low <= high) {
            int mid = (low + high) >> 1;
            if (sum[mid] - sum[i] >= dp[i].se) {
                k = mid;
                high = mid - 1;
            }
            else {
                low = mid + 1;
            }
        }
        if (k <= n) {
            update(dp[k], {dp[i].fi + 1, sum[k] - sum[i]});
        }
    }

    cout << dp[n].fi;

    return 0;
}

/*


*/

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 10 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27