제출 #339866

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
339866		Vladikus004	등산 경로 (IZhO12_route)	C++14	0 / 100	17 ms	2792 KiB

route

#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define inf 2e9
using namespace std;
typedef long long ll;
typedef pair <int, int> pii;

//#define int long long
const int N = 1000000 + 3;
int n, k, a[N], b[N], cnt[N], buff[N];

ll solve(int k){
    vector <int> st;
    for (int i = n - 1; i >= 0; i--)
        if (b[i] > 0) st.pb(i);
    for (int i = n - 1; i >= 0; i--){
        while (!st.empty() && b[st.back()] == 0) st.pop_back();
        if (b[i] > 0) st.push_back(i);
        if (b[i] < 0){
            while (b[i] < 0 && !st.empty()){
                int gt = min(-b[i], b[st.back()]);
                cnt[(st.back() + n - i) % n] += gt;
                b[st.back()] -= gt;
                b[i] += gt;
                while (!st.empty() && b[st.back()] == 0) st.pop_back();
            }
        }
    }
    ll ans = 0;
    for (int i = 1; i <= n; i++){
        int gt = min(k/i, cnt[i]);
        k -= i * 1LL * gt;
        cnt[i] -= gt;
        ans += gt;
        cnt[i] = 0;
    }
    return ans*2LL;
}

int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
//    freopen("input.txt", "r", stdin);
    cin >> n >> k;
    pair <ll, ll> mx = {-1, -1};
    for (int i = 0; i < n; i++) cin >> a[i];
    for (int i = 0; i < n - 1; i++) b[i] = a[i + 1] - a[i];
    b[n - 1] = a[0] - a[n - 1];
    ll pref = 0;
    for (int i = 0; i < n; i++){
        pref += b[i];
        mx = max(mx, {pref, i});
    }
    int cnt = 0;
    for (int i = mx.second; i < n; i++)
        buff[cnt++] = b[i];
    for (int i = 0; i < mx.second; i++)
        buff[cnt++] = b[i];
    for (int i = 0; i < n; i++)
        b[i] = buff[i];
    b[n] = b[0];
    for (int j = 0; j < n; j++)
        b[j] = b[j + 1];
    ll ans = 0;
        ans = max(ans, solve(k));
    cout << ans;
    return 0;
}

• Subtask 1: 0 / 100