AtCoder Regular Contest 193 (Div. 1)
A
Complement Interval Graph
AtCoder
⌀ 1234
原题
←B →
翻译中…

Problem Statement

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For integers $l, r$, let $[l, r]$ denote the set of all integers from $l$ through $r$. That is, $[l, r] = \lbrace l, l+1, l+2, \ldots, r-1, r\rbrace$.

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You are given $N$ pairs of integers $(L_1, R_1), (L_2, R_2), \ldots, (L_N, R_N)$. Based on these pairs, consider an undirected graph $G$ defined as follows:

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  • It has $N$ vertices numbered $1, 2, \ldots, N$.
  • For all $i, j \in [1, N]$, there is an undirected edge between vertices $i$ and $j$ if and only if the intersection of $[L_i, R_i]$ and $[L_j, R_j]$ is empty.
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In addition, for each $i = 1, 2, \ldots, N$, define the weight of vertex $i$ to be $W_i$.

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You are given $Q$ queries about $G$. Process these queries in the order they are given. For each $i = 1, 2, \ldots, Q$, the $i$-th query is the following:

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You are given integers $s_i$ and $t_i$ (both between $1$ and $N$, inclusive) such that $s_i \neq t_i$. Determine whether there exists a path from vertex $s_i$ to vertex $t_i$ in $G$. If it exists, print the minimum possible weight of such a path.

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Here, the weight of a path from vertex $s$ to vertex $t$ is defined as the sum of the weights of the vertices on that path (including both endpoints $s$ and $t$).

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Constraints

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  • $2 \leq N \leq 2 \times 10^5$
  • $1 \leq Q \leq 2 \times 10^5$
  • $1 \leq W_i \leq 10^9$
  • $1 \leq L_i \leq R_i \leq 2N$
  • $1 \leq s_i, t_i \leq N$
  • $s_i \neq t_i$
  • All input values are integers.
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Input

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The input is given from Standard Input in the following format:

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N
W_1 W_2 \cdots W_N
L_1 R_1
L_2 R_2
\vdots
L_N R_N
Q
s_1 t_1
s_2 t_2
\vdots
s_Q t_Q

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Output

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Print $Q$ lines. For each $i = 1, 2, \ldots, Q$, on the $i$-th line, if there exists a path from vertex $s_i$ to vertex $t_i$, print the minimum possible weight of such a path, and print -1 otherwise.

翻译中…

样例

Input #1
5
5 1 4 2 2
2 4
1 2
7 8
4 5
2 7
3
1 4
4 3
5 2
Output #1
11
6
-1
$G$ is a graph with four undirected edges: $\lbrace 1, 3\rbrace, \lbrace 2, 3\rbrace, \lbrace 2, 4\rbrace, \lbrace 3, 4\rbrace$. - For the first query, there is a path from vertex $1$ to vertex $4$ given by $1 \to 3 \to 4$. The weight of this path is $W_1 + W_3 + W_4 = 5 + 4 + 2 = 11$, and this is the minimum possible. - For the second query, there is a path from vertex $4$ to vertex $3$ given by $4 \to 3$. The weight of this path is $W_4 + W_3 = 2 + 4 = 6$, and this is the minimum possible. - For the third query, there is no path from vertex $5$ to vertex $2$. Hence, print `-1`.
Input #2
8
44 75 49 4 78 79 12 32
5 13
10 16
6 8
6 15
12 15
5 7
1 15
1 2
5
5 6
3 2
7 5
4 5
5 4
Output #2
157
124
-1
114
114
题目信息
题号
arc193_a
时间限制
2 s
内存限制
1024 MB

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