Submission #163898

#	Time	Username	Problem	Language	Result	Execution time	Memory
163898		ho94949	Triple Jump (JOI19_jumps)	C++17	27 / 100	100 ms	9572 KiB

jumps

#include<bits/stdc++.h>

using namespace std;
const int MAXN = 524288;
int N;
int A[MAXN];
int nv[MAXN];
int idx[2*MAXN];
int getv(int a, int b)
{
    a += MAXN; b += MAXN;
    int ans = 0; 
    while(a<=b)
    {
        if(a%2==1) ans = max(ans, idx[a++]);
        if(b%2==0) ans = max(ans, idx[b--]);
        a/=2; b/=2;
    }
    return ans;
}
void setv(int a, int v)
{
    idx[a+=MAXN] = v;
    while((a=a/2))
        idx[a] = max(idx[2*a], idx[2*a+1]);
}
int solve()
{
    A[N] = (int)1e8+1;
    stack<int> S;
    for(int i=0; i<=N; ++i)
    {
        setv(i, A[i]);
        while(!S.empty() && A[S.top()] < A[i])
        {
            nv[S.top()] = i; S.pop();
        }
        S.push(i);
    }
    vector<pair<int, int> > ab;
    for(int a=0; a<N-1; ++a)
    {
        int b = a+1;
        ab.emplace_back(a, b);
        while(nv[b] != N && A[b]<A[a])
        {
            b = nv[b];
            ab.emplace_back(a, b);
        }
    }
    int ret = 0;
    for(auto [a, b]: ab)
    {
        int cind = 2*b-a;
        int ans = A[a] + A[b] + getv(cind, N-1);
        ret = max(ret, ans);
    }
    return ret;
}
int main()
{
    scanf("%d", &N);
    for(int i=0; i<N; ++i) scanf("%d", A+i);
    int Q; scanf("%d", &Q); assert(Q==1);
    int L, R; scanf("%d%d", &L, &R);
    assert(L==1&&R==N);
    printf("%d\n", solve());
    return 0;
}

Compilation message (stderr)

jumps.cpp: In function 'int main()':
jumps.cpp:62:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &N);
     ~~~~~^~~~~~~~~~
jumps.cpp:63:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(int i=0; i<N; ++i) scanf("%d", A+i);
                            ~~~~~^~~~~~~~~~~
jumps.cpp:64:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     int Q; scanf("%d", &Q); assert(Q==1);
            ~~~~~^~~~~~~~~~
jumps.cpp:65:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     int L, R; scanf("%d%d", &L, &R);
               ~~~~~^~~~~~~~~~~~~~~~

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