제출 #176033

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
176033		mcdx9524	Bigger segments (IZhO19_segments)	C++14	100 / 100	122 ms	14224 KiB

segments

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

mt19937 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());

int rand(int l, int r) {
    return uniform_int_distribution <int> (l, r) (rnd);
}

const int inf = 1e9 + 7;

void solve() {
    int n;
    cin >> n;
    vector <int> a(n + 1, 0);
    vector <ll> pref(n + 1, 0);
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        pref[i] = a[i] + pref[i - 1];
    }
    vector <pair <int, ll> > dp(n + 1, {0, inf});
    dp[0] = {0, 0};
    for (int i = 0; i <= n; i++) {
        if (i >= 1) {
            ll sum = a[i];
            if (dp[i - 1].first > dp[i].first) {
                dp[i].first = dp[i - 1].first;
                dp[i].second = dp[i - 1].second + a[i];
            } else if (dp[i - 1].first == dp[i].first) {
                dp[i].second = min(dp[i].second, dp[i - 1].second + a[i]);
            }
        }
        int l = i + 1, r = n;
        int ans = -1;
        while (l <= r) {
            int m = (l + r) / 2;
            if (pref[m] - pref[i] >= dp[i].second) {
                ans = m;
                r = m - 1;
            } else {
                l = m + 1;
            }
        }
        if (ans == -1) {
            continue;
        }
        ll sum = pref[ans] - pref[i];
        if (sum >= dp[i].second) {
            if (dp[i].first + 1 > dp[ans].first) {
                dp[ans].first = dp[i].first + 1;
                dp[ans].second = sum;
            } else if (dp[i].first + 1 == dp[ans].first) {
                dp[ans].second = min(dp[ans].second, sum);
            }
        }
    }
    cout << dp[n].first << '\n';
}

int main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    int test_cnt = 1;
    //cin >> test_cnt;
    while (test_cnt--) {
        solve();
    }
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

segments.cpp: In function 'void solve()':
segments.cpp:28:16: warning: unused variable 'sum' [-Wunused-variable]
             ll sum = a[i];
                ^~~

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