AtCoder Beginner Contest 286——A - Range Swap

AtCoder Beginner Contest 286 题目讲解

A题 B题 C题 D题 E题

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蒟蒻来讲题，还望大家喜。若哪有问题，大家尽可提！

Hello, 大家好哇！本初中生蒟蒻今天讲解一下AtCoder Beginner Contest 286的A题——Range Swap

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原题

Problem Statement

You are given a sequence $A=(A_1,A_2,\dots ,A_N)$ of length $N$ and positive integers $P,Q,R$, and $S$.
Here, $P$,$Q$,$R$, and $S$ satisfy $1\le P\le Q<R\le S\le N$ and $Q-P=S-R.$

Let $B=(B_1,B_2,\dots ,B_N)$ be the sequence obtained by swapping the $P$-th through $Q$-th terms and the $R$-th through $S$-th terms of $A$.
Print the sequence $B$.

Constraints

• $1\le N\le 100$
• $1\le A_i\le 100$
• $1\le P\le Q<R\le S\le N$
• $Q-P=S-R$
• All values in the input are integers.

Input

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

N  P Q R S
A1​ A2​ … AN​

Output

Print $B_1,B_2,\dots ,B_N$​, with spaces in between.

Sample Input 1

8 1 3 5 7
1 2 3 4 5 6 7 8

Sample Output 1

5 6 7 4 1 2 3 8

Swapping the $1$-st through $3$-rd terms $(1,2,3)$ and the $5$-th through $7$-th terms $(5,6,7)$ of the sequence $A=(1,2,3,4,5,6,7,8)$ results in $B=(5,6,7,4,1,2,3,8)$, which should be printed with spaces in between.

Sample Input 2

5 2 3 4 5
2 2 1 1 1

Sample Output 2

2 1 1 2 1

The same integer may occur multiple times in the sequence.

Sample Input 3

2 1 1 2 2
50 100

Sample Output 3

100 50

Sample Input 4

10 2 4 7 9
22 75 26 45 72 81 47 29 97 2

Sample Output 4

22 47 29 97 72 81 75 26 45 2

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思路

因为就只要更改2个区间，所以整个序列分成5个段，依次输出即可。（详情请看代码）

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代码

#include 

using namespace std;

const int N = 1e2 + 10;

int n, p, q, r, s;
int a[N];


int main()
{
	cin >> n >> p >> q >> r >> s;
	
	for (int i = 1; i <= n; i ++)	
		cin >> a[i];
		
	for (int i = 1; i < p; i ++)//区间1之前的位置 
		cout << a[i] << " ";
		
	for (int i = r; i <= s; i ++) //区间1的位置输出区间2的元素的值
		cout <<a[i] << " ";
		
	for (int i = q + 1; i < r; i ++)//区间1与2之间的值
		cout << a[i] << " ";
		
	for (int i = p; i <= q; i ++)//区间2的位置输出区间1的元素的值
		cout << a[i] << " ";
		
	for (int i = s + 1; i <= n; i ++) //区间2之后的位置的值
		cout << a[i] << " ";

	return 0;
}

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今天就到这里了！

大家有什么问题尽管提，我都会尽力回答的！最后，除夕夜祝大家新年快乐！

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