Submission #147253

#	Time	Username	Problem	Language	Result	Execution time	Memory
147253		Alexa2001	Triple Jump (JOI19_jumps)	C++17	19 / 100	4069 ms	19560 KiB

jumps

#include <bits/stdc++.h>

using namespace std;

const int Nmax = 5e5 + 5;
const int inf = 1e9;

vector<pair<int,int>> v;
int a[Nmax], st[Nmax];
int n, L[Nmax], R[Nmax];
int Ans[Nmax];

void fnd()
{
    int i, nr = 0;

    st[0] = 0;
    a[0] = inf;

    for(i=1; i<=n; ++i)
    {
        while(a[st[nr]] <= a[i])
        {
            v.push_back({st[nr], i});
            --nr;
        }

        v.push_back({st[nr], i});
        st[++nr] = i;
    }
}

int best(int x, int y)
{
    int i; int ans = 0;
    for(i=x; i<=y; ++i) ans = max(ans, a[i]);
    return ans;
}

void solv(int R, vector<int> &queries)
{
    int i; 
    vector<int> best(R+2);

    best[R+1] = -1e9;
    for(i=R; i; --i) best[i] = max(best[i+1], a[i]);
   
    vector<int> coef(v.size());

    for(i=0; i<v.size(); ++i)
        coef[i] = a[v[i].first] + a[v[i].second] + best[ min(R+1, 2 * v[i].second - v[i].first)  ];
    
    int j = v.size() - 1;
    int now = 0;

    vector<int> wow(R+2);

    for(i=R; i; --i)
    {
        while(j>=0 && v[j].first >= i) now = max(now, coef[j]), --j;
        wow[i] = now;
    }

    for(auto it : queries)
        Ans[it] = wow[L[it]];
}

int main()
{
  //  freopen("triple.in", "r", stdin);
    cin.tie(0); cin.sync_with_stdio(false);
    
    cin >> n;

    int i, q;
    for(i=1; i<=n; ++i) cin >> a[i];

    cin >> q;
    for(i=1; i<=q; ++i) cin >> L[i] >> R[i];

    fnd();
    
    vector<vector<int>> endp(n+1);

    sort(v.begin(), v.end());

    for(i=1; i<=q; ++i)
        endp[R[i]].push_back(i);
    
    for(i=1; i<=n; ++i)
        solv(i, endp[i]);
    
    for(i=1; i<=q; ++i) cout << Ans[i] << '\n';
    return 0;
}

Compilation message (stderr)

jumps.cpp: In function 'void solv(int, std::vector<int>&)':
jumps.cpp:50:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(i=0; i<v.size(); ++i)
              ~^~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 14 / 14
• Subtask 3: 0 / 27
• Subtask 4: 0 / 54