Submission #200500

#	Time	Username	Problem	Language	Result	Execution time	Memory
200500		arnold518	Triple Jump (JOI19_jumps)	C++14	27 / 100	187 ms	54756 KiB

jumps

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 5e5;
const ll INF = 1e18;

int N, Q;
ll A[MAXN+10], B[MAXN+10], ans[MAXN+10];
vector<pii> V;

struct Query { int l, r, p; };
Query query[MAXN+10];

struct Node
{
	ll A, B, BA;
	Node() : A(-INF), B(-INF), BA(-INF) {}
};

Node add(Node lc, Node rc)
{
	Node ret;
	ret.BA=max({lc.BA, rc.BA, lc.B+rc.A});
	ret.A=max(lc.A, rc.A);
	ret.B=max(lc.B, rc.B);
	return ret;
}

Node tree[MAXN*4+10];

void init(int node, int tl, int tr)
{
	if(tl==tr)
	{
		tree[node].A=A[tl];
		tree[node].B=B[tl];
		tree[node].BA=A[tl]+B[tl];
		return;
	}
	int mid=tl+tr>>1;
	init(node*2, tl, mid);
	init(node*2+1, mid+1, tr);
	tree[node]=add(tree[node*2], tree[node*2+1]);
}

void update(int node, int tl, int tr, int pos)
{
	if(tl==tr)
	{
		tree[node].A=A[tl];
		tree[node].B=B[tl];
		tree[node].BA=A[tl]+B[tl];
		return;
	}
	int mid=tl+tr>>1;
	if(pos<=mid) update(node*2, tl, mid, pos);
	else update(node*2+1, mid+1, tr, pos);
	tree[node]=add(tree[node*2], tree[node*2+1]);
}

Node qquery(int node, int tl, int tr, int l, int r)
{
	if(l<=tl && tr<=r) return tree[node];
	if(r<tl || tr<l) return Node();
	int mid=tl+tr>>1;
	return add(qquery(node*2, tl, mid, l, r), qquery(node*2+1, mid+1, tr, l, r));
}

int main()
{
	int i, j, k;
	scanf("%d", &N);
	for(i=1; i<=N; i++) scanf("%lld", &A[i]), B[i]=-INF;
	scanf("%d", &Q);
	for(i=1; i<=Q; i++) scanf("%d%d", &query[i].l, &query[i].r), query[i].p=i;

	vector<int> S;
	for(i=1; i<=N; i++)
	{
		while(!S.empty() && A[S.back()]<=A[i]) V.push_back({S.back(), i}), S.pop_back();
		if(!S.empty()) V.push_back({S.back(), i});
		S.push_back(i);
	}

	sort(V.begin(), V.end(), greater<pii>());
	sort(query+1, query+Q+1, [&](const Query &p, const Query &q) { return p.l>q.l; });

	init(1, 1, N);

	//for(auto it : V) printf("%d %d\n", it.first, it.second);

	for(i=N, j=0, k=1; i>=1; i--)
	{
		for(; j<V.size() && V[j].first==i; j++)
		{
			int t=V[j].second*2-V[j].first;
			if(t>N) continue;
			B[t]=A[V[j].first]+A[V[j].second];
			update(1, 1, N, t);
		}
		for(; k<=Q && query[k].l==i; k++)
		{
			ans[query[k].p]=qquery(1, 1, N, query[k].l, query[k].r).BA;
		}
	}
	for(i=1; i<=Q; i++) printf("%lld\n", ans[i]);
}

Compilation message (stderr)

jumps.cpp: In function 'void init(int, int, int)':
jumps.cpp:44:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=tl+tr>>1;
          ~~^~~
jumps.cpp: In function 'void update(int, int, int, int)':
jumps.cpp:59:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=tl+tr>>1;
          ~~^~~
jumps.cpp: In function 'Node qquery(int, int, int, int, int)':
jumps.cpp:69:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=tl+tr>>1;
          ~~^~~
jumps.cpp: In function 'int main()':
jumps.cpp:98:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(; j<V.size() && V[j].first==i; j++)
         ~^~~~~~~~~
jumps.cpp:76:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
jumps.cpp:77:42: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(i=1; i<=N; i++) scanf("%lld", &A[i]), B[i]=-INF;
                      ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
jumps.cpp:78:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &Q);
  ~~~~~^~~~~~~~~~
jumps.cpp:79:61: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(i=1; i<=Q; i++) scanf("%d%d", &query[i].l, &query[i].r), query[i].p=i;
                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~

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