Codeforces Round 763 (Div. 2)
B
Game on Ranges
Codeforces
1100
原题
← AC →
翻译中…

Alice and Bob play the following game. Alice has a set $S$ of disjoint ranges of integers, initially containing only one range $[1, n]$. In one turn, Alice picks a range $[l, r]$ from the set $S$ and asks Bob to pick a number in the range. Bob chooses a number $d$ ($l \le d \le r$). Then Alice removes $[l, r]$ from $S$ and puts into the set $S$ the range $[l, d - 1]$ (if $l \le d - 1$) and the range $[d + 1, r]$ (if $d + 1 \le r$). The game ends when the set $S$ is empty. We can show that the number of turns in each game is exactly $n$.

翻译中…

After playing the game, Alice remembers all the ranges $[l, r]$ she picked from the set $S$, but Bob does not remember any of the numbers that he picked. But Bob is smart, and he knows he can find out his numbers $d$ from Alice's ranges, and so he asks you for help with your programming skill.

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Given the list of ranges that Alice has picked ($[l, r]$), for each range, help Bob find the number $d$ that Bob has picked.

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We can show that there is always a unique way for Bob to choose his number for a list of valid ranges picked by Alice.

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Input

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Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 1000$). Description of the test cases follows.

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The first line of each test case contains a single integer $n$ ($1 \le n \le 1000$).

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Each of the next $n$ lines contains two integers $l$ and $r$ ($1 \le l \le r \le n$), denoting the range $[l, r]$ that Alice picked at some point.

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Note that the ranges are given in no particular order.

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It is guaranteed that the sum of $n$ over all test cases does not exceed $1000$, and the ranges for each test case are from a valid game.

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Output

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For each test case print $n$ lines. Each line should contain three integers $l$, $r$, and $d$, denoting that for Alice's range $[l, r]$ Bob picked the number $d$.

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You can print the lines in any order. We can show that the answer is unique.

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It is not required to print a new line after each test case. The new lines in the output of the example are for readability only.

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Note

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In the first test case, there is only 1 range $[1, 1]$. There was only one range $[1, 1]$ for Alice to pick, and there was only one number $1$ for Bob to pick.

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In the second test case, $n = 3$. Initially, the set contains only one range $[1, 3]$.

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  • Alice picked the range $[1, 3]$. Bob picked the number $1$. Then Alice put the range $[2, 3]$ back to the set, which after this turn is the only range in the set.
  • Alice picked the range $[2, 3]$. Bob picked the number $3$. Then Alice put the range $[2, 2]$ back to the set.
  • Alice picked the range $[2, 2]$. Bob picked the number $2$. The game ended.
翻译中…

In the fourth test case, the game was played with $n = 5$. Initially, the set contains only one range $[1, 5]$. The game's turn is described in the following table.

翻译中…

Game turnAlice's picked rangeBob's picked number****The range set afterBefore the game start$ \{ [1, 5] \} $1$[1, 5]$$3$$ \{ [1, 2], [4, 5] \}$2$[1, 2]$$1$$ \{ [2, 2], [4, 5] \} $3$[4, 5]$$5$$ \{ [2, 2], [4, 4] \} $4$[2, 2]$$2$$ \{ [4, 4] \} $5$[4, 4]$$4$$ \{ \} $ (empty set)

翻译中…

样例

Input #1
4
1
1 1
3
1 3
2 3
2 2
6
1 1
3 5
4 4
3 6
4 5
1 6
5
1 5
1 2
4 5
2 2
4 4
Output #1
1 1 1

1 3 1
2 2 2
2 3 3

1 1 1
3 5 3
4 4 4
3 6 6
4 5 5
1 6 2

1 5 3
1 2 1
4 5 5
2 2 2
4 4 4
InputCopy OutputCopy
题目信息
题号
1623B
时间限制
1 s
内存限制
256 MB
标签
暴力
DFS 及类似
模拟
排序

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。