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@anonymously115

paizaラーニングレベルアップ問題集の「変数/要素の入れ替え」をやってみた。

Last updated at Posted at 2025-06-22

paizaラーニングレベルアップ問題集の「変数/要素の入れ替え」をやってみました。

問題
2変数の入れ替え

変数の入れ替え

配列の要素の入れ替え

指定要素の入れ替え

方針
2変数の入れ替え
  • 変数名は$A$，$B$です
  • 入力値は1以上10以下です
変数の入れ替え
  • 変数名は$X$，$Y$です
  • 入力値は0以上100以下です
配列の要素の入れ替え
  • 配列は半角空白区切り（ヨコ入力）で与えられます
  • 配列の各要素は1以上10以下です
  • 要素番号は最初に与えられます
指定要素の入れ替え
  • 配列は改行区切り（タテ入力）で与えられます
  • 配列の各要素は0以上100以下です
  • 要素番号は最後に与えられます
C
2変数の入れ替え
#include <stdio.h>

void swap(int* a, int* b) {
	int tmp = *a;
	*a = *b;
	*b = tmp;
}

int main() {
	int a, b;
	scanf("%d %d", &a, &b);
	swap(&a, &b);
	printf("%d %d\n", a, b);
	return 0;
}
変数の入れ替え
#include <stdio.h>

void swap(int* x, int* y) {
	int tmp = *x;
	*x = *y;
	*y = tmp;
}

int main() {
	int x, y;
	scanf("%d %d", &x, &y);
	swap(&x, &y);
	printf("%d %d\n", x, y);
	return 0;
}
配列の要素の入れ替え
#include <stdio.h>

void swap(int A[], int i, int j) {
	int tmp = A[i];
	A[i] = A[j];
	A[j] = tmp;
}

int main() {
	int x, y, n;
	scanf("%d %d %d", &x, &y, &n);
	x -= 1;
	y -= 1;
	int A[n];
	for (int i = 0; i < n; i++) scanf("%d", &A[i]);
	swap(A, x, y);
	for (int i = 0; i < n; i++) printf("%d\n", A[i]);
	return 0;
}
指定要素の入れ替え
#include <stdio.h>

void swap(int A[], int i, int j) {
	int tmp = A[i];
	A[i] = A[j];
	A[j] = tmp;
}

int main() {
	int n;
	scanf("%d", &n);
	int A[n];
	for (int i = 0; i < n; i++) scanf("%d", &A[i]);
	int x, y;
	scanf("%d %d", &x, &y);
	x -= 1;
	y -= 1;
	swap(A, x, y);
	for (int i = 0; i < n; i++) printf("%d\n", A[i]);
	return 0;
}
C++
2変数の入れ替え
#include <iostream>
#include <utility>
using namespace std;

int main() {
	int a, b;
	cin >> a >> b;
	swap(a, b);
	cout << a << ' ' << b << endl;
	return 0;
}
変数の入れ替え
#include <iostream>
#include <utility>
using namespace std;

int main() {
	int x, y;
	cin >> x >> y;
	swap(x, y);
	cout << x << ' ' << y << endl;
	return 0;
}
配列の要素の入れ替え
#include <iostream>
#include <vector>
#include <utility>
using namespace std;

int main() {
	int x, y, n;
	cin >> x >> y >> n;
	x -= 1;
	y -= 1;
	vector<int> A(n);
	for (int i = 0; i < n; i++) cin >> A[i];
	swap(A[x], A[y]);
	for (int i = 0; i < n; i++) cout << A[i] << endl;
	return 0;
}
指定要素の入れ替え
#include <iostream>
#include <vector>
#include <utility>
using namespace std;

int main() {
	int n;
	cin >> n;
	vector<int> A(n);
	for (int i = 0; i < n; i++) cin >> A[i];
	int x, y;
	cin >> x >> y;
	x -= 1;
	y -= 1;
	swap(A[x], A[y]);
	for (int i = 0; i < n; i++) cout << A[i] << endl;
	return 0;
}
C#
2変数の入れ替え
using System;

class Program
{
	static void Swap(ref int a, ref int b) {
		int tmp = a;
		a = b;
		b = tmp;
	}
	
	public static void Main()
	{
		int[] ab = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
		int a = ab[0], b = ab[1];
		Swap(ref a, ref b);
		Console.WriteLine("" + a + ' ' + b);
	}
}
変数の入れ替え
using System;

class Program
{
	static void Swap(ref int x, ref int y) {
		int tmp = x;
		x = y;
		y = tmp;
	}
	
	public static void Main()
	{
		int[] xy = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
		int x = xy[0], y = xy[1];
		Swap(ref x, ref y);
		Console.WriteLine("" + x + ' ' + y);
	}
}
配列の要素の入れ替え
using System;

class Program
{
	private static void Swap(int[] A, int i, int j) {
		int tmp = A[i];
		A[i] = A[j];
		A[j] = tmp;
	}
	
	public static void Main()
	{
		int[] xyn = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
		int x = xyn[0] - 1, y = xyn[1] - 1;
		int[] A = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
		Swap(A, x, y);
		foreach (int a in A) Console.WriteLine(a);
	}
}
指定要素の入れ替え
using System;
using System.Linq;

class Program
{
	private static void Swap(int[] A, int i, int j) {
		int tmp = A[i];
		A[i] = A[j];
		A[j] = tmp;
	}
	
	public static void Main()
	{
		int[] A = Enumerable.Range(0, int.Parse(Console.ReadLine())).Select(_ => int.Parse(Console.ReadLine())).ToArray();
		int[] xy = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
		int x = xy[0] - 1, y = xy[1] - 1;
		Swap(A, x, y);
		foreach (int a in A) Console.WriteLine(a);
	}
}
Go
2変数の入れ替え
package main
import "fmt"

func main() {
	var a, b int
	fmt.Scan(&a, &b)
	a, b = b, a
	fmt.Println(a, b)
}
変数の入れ替え
package main
import "fmt"

func main() {
	var x, y int
	fmt.Scan(&x, &y)
	x, y = y, x
	fmt.Println(x, y)
}
配列の要素の入れ替え
package main
import "fmt"

func main() {
	var x, y, n int
	fmt.Scan(&x, &y, &n)
	x -= 1
	y -= 1
	A := make([]int, n)
	for i := 0; i < n; i++ {
		fmt.Scan(&A[i])
	}
	A[x], A[y] = A[y], A[x]
	for i := 0; i < n; i++ {
		fmt.Println(A[i])
	}
}
指定要素の入れ替え
package main
import "fmt"

func main() {
	var n int
	fmt.Scan(&n)
	A := make([]int, n)
	for i := 0; i < n; i++ {
		fmt.Scan(&A[i])
	}
	var x, y int
	fmt.Scan(&x, &y)
	x -= 1
	y -= 1
	A[x], A[y] = A[y], A[x]
	for i := 0; i < n; i++ {
		fmt.Println(A[i])
	}
}
Java
2変数の入れ替え
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		sc.close();
		int tmp = a;
		a = b;
		b = tmp;
		System.out.println("" + a + ' ' + b);
	}
}
変数の入れ替え

無理矢理swap関数を作ってみました。

import java.util.*;

public class Main {
	private static void swap(int[] X, int[] Y) {
		int tmp = X[0];
		X[0] = Y[0];
		Y[0] = tmp;
	}
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int y = sc.nextInt();
		sc.close();		
		int[] X = {x};
		int[] Y = {y};
		swap(X, Y);
		System.out.println("" + X[0] + ' ' + Y[0]);
	}
}
配列の要素の入れ替え
import java.util.*;

public class Main {
	private static void swap(int[] A, int i, int j) {
		int tmp = A[i];
		A[i] = A[j];
		A[j] = tmp;
	}
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt() - 1;
		int y = sc.nextInt() - 1;
		int n = sc.nextInt();
		sc.nextLine();
		int[] A = Arrays.stream(sc.nextLine().split(" ")).mapToInt(Integer::parseInt).toArray();
		sc.close();
		swap(A, x, y);
		for (int i = 0; i < n; i++) System.out.println(A[i]);
	}
}
指定要素の入れ替え
import java.util.*;
import java.util.stream.IntStream;

public class Main {
	private static void swap(int[] A, int i, int j) {
		int tmp = A[i];
		A[i] = A[j];
		A[j] = tmp;
	}
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] A = IntStream.range(0, n).map(i -> sc.nextInt()).toArray();
		int x = sc.nextInt() - 1;
		int y = sc.nextInt() - 1;
		sc.close();
		swap(A, x, y);
		for (int i = 0; i < n; i++) System.out.println(A[i]);
	}
}
JavaScript
2変数の入れ替え
let [a, b] = require("fs").readFileSync("/dev/stdin", "utf8").split(' ').map(Number);
[a, b] = [b, a];
console.log(a, b);
変数の入れ替え
let [x, y] = require("fs").readFileSync("/dev/stdin", "utf8").split(' ').map(Number);
[x, y] = [y, x];
console.log(x, y);
配列の要素の入れ替え
let [[x, y, n], A] = require("fs").readFileSync("/dev/stdin", "utf8").trim().split('\n').map(s => s.split(' ').map(Number));
x -= 1;
y -= 1;
[A[x], A[y]] = [A[y], A[x]];
for (var i = 0; i < n; i++) console.log(A[i]);
指定要素の入れ替え
const lines = require("fs").readFileSync("/dev/stdin", "utf8").trim().split('\n');
const n = Number(lines.shift());
const [x, y] = lines.pop().split(' ').map(s => Number(s) - 1);
const A = lines.map(Number);
[A[x], A[y]] = [A[y], A[x]];
for (var i = 0; i < n; i++) console.log(A[i]);
Kotlin
2変数の入れ替え
fun main() {
	var (a, b) = readLine()!!.split(' ').map { it.toInt() }
	val tmp = a
	a = b
	b = tmp
	println("" + a + ' ' + b)
}
変数の入れ替え
fun main() {
	var (x, y) = readLine()!!.split(' ').map { it.toInt() }
	val tmp = x
	x = y
	y = tmp
	println("" + x + ' ' + y)
}
配列の要素の入れ替え
fun main() {
	var (x, y, n) = readLine()!!.split(' ').map { it.toInt() }
	x -= 1
	y -= 1
	val A = readLine()!!.split(' ').map { it.toInt() }.toTypedArray()
	A[x] = A[y].also { A[y] = A[x] }
	for (i in 0 until n) println(A[i])
}
指定要素の入れ替え
fun main() {
	val n = readLine()!!.toInt()
	val A = Array(n) { readLine()!!.toInt() }
	val (x, y) = readLine()!!.split(' ').map { it.toInt() - 1 }
	A[x] = A[y].also { A[y] = A[x] }
	for (i in 0 until n) println(A[i])
}
PHP
2変数の入れ替え
<?php
	[$a, $b] = array_map("intval", explode(' ', trim(fgets(STDIN))));
	[$a, $b] = [$b, $a];
	echo $a, ' ', $b, PHP_EOL;
?>
変数の入れ替え
<?php
	[$x, $y] = array_map("intval", explode(' ', trim(fgets(STDIN))));
	[$x, $y] = [$y, $x];
	echo $x, ' ', $y, PHP_EOL;
?>
配列の要素の入れ替え
<?php
	[$x, $y, $n] = array_map("intval", explode(' ', trim(fgets(STDIN))));
	$x -= 1;
	$y -= 1;
	$A = array_map("intval", explode(' ', trim(fgets(STDIN))));
	[$A[$x], $A[$y]] = [$A[$y], $A[$x]];
	for ($i = 0; $i < $n; $i++)	echo $A[$i], PHP_EOL;
?>
指定要素の入れ替え
<?php
	$n = intval(fgets(STDIN));
	$A = [];
	for ($i = 0; $i < $n; $i++) $A[] = intval(fgets(STDIN));
	[$x, $y] = array_map(fn($s) => intval($s) - 1, explode(' ', trim(fgets(STDIN))));
	[$A[$x], $A[$y]] = [$A[$y], $A[$x]];
	for ($i = 0; $i < $n; $i++)	echo $A[$i], PHP_EOL;
?>
Perl
2変数の入れ替え
my ($a, $b) = map { int($_) } split ' ', <STDIN>;
($a, $b) = ($b, $a);
print "$a $b$/";
変数の入れ替え
my ($x, $y) = map { int($_) } split ' ', <STDIN>;
($x, $y) = ($y, $x);
print "$x $y$/";
配列の要素の入れ替え
my ($x, $y, $n) = map { int($_) } split ' ', <STDIN>;
$x -= 1;
$y -= 1;
my @A = map { int($_) } split ' ', <STDIN>;
($A[$x], $A[$y]) = ($A[$y], $A[$x]);
for ($i = 0; $i < $n; $i++) {
	print $A[$i], $/;
}
指定要素の入れ替え
my $n = int(<STDIN>);
my @A;
for (1..$n) {
	push @A, int(<STDIN>);
}
my ($x, $y) = map { int($_) - 1 } split ' ', <STDIN>;
($A[$x], $A[$y]) = ($A[$y], $A[$x]);
for ($i = 0; $i < $n; $i++) {
	print $A[$i], $/;
}
Python3
2変数の入れ替え
a, b = map(int, input().split())
a, b = b, a
print(a, b)
変数の入れ替え
x, y = map(int, input().split())
x, y = y, x
print(x, y)
配列の要素の入れ替え
x, y, n = map(int, input().split())
x -= 1
y -= 1
A = list(map(int, input().split()))
A[x], A[y] = A[y], A[x]
for i in range(n):
	print(A[i])
指定要素の入れ替え
n = int(input())
A = [int(input()) for _ in range(n)]
x, y = map(lambda s: int(s) - 1, input().split())
A[x], A[y] = A[y], A[x]
for i in range(n):
	print(A[i])
Ruby
2変数の入れ替え
a, b = gets.split.map(&:to_i)
a, b = b, a
print a, ' ', b, "\n"
変数の入れ替え
x, y = gets.split.map(&:to_i)
x, y = y, x
print x, ' ', y, "\n"
配列の要素の入れ替え
x, y, n = gets.split.map(&:to_i)
x -= 1
y -= 1
A = gets.split.map(&:to_i)
A[x], A[y] = A[y], A[x]
n.times do |i|
	p A[i]
end
指定要素の入れ替え
n = gets.to_i
A = n.times.map { gets.to_i }
x, y = gets.split.map { |s| s.to_i - 1 }
A[x], A[y] = A[y], A[x]
n.times do |i|
	p A[i]
end
Scala
2変数の入れ替え
import scala.io.StdIn._

object Main extends App{
	var Array(a, b) = readLine().split(' ').map { _.toInt }
	val tmp = a
	a = b
	b = tmp
	println("" + a + ' ' + b)
}
変数の入れ替え
import scala.io.StdIn._

object Main extends App{
	var Array(x, y) = readLine().split(' ').map { _.toInt }
	val tmp = x
	x = y
	y = tmp
	println("" + x + ' ' + y)
}
配列の要素の入れ替え
import scala.io.StdIn._

object Main extends App{
	def swap(A: Array[Int], x: Int, y: Int) = {
		val tmp = A(x)
		A(x) = A(y)
		A(y) = tmp
	}
	var Array(x, y, n) = readLine().split(' ').map { _.toInt }
	x -= 1
	y -= 1
	val A = readLine().split(' ').map { _.toInt }
	swap(A, x, y)
	for (i <- 0 until n) println(A(i))
}
指定要素の入れ替え
import scala.io.StdIn._

object Main extends App{
	def swap(A: Array[Int], x: Int, y: Int) = {
		val tmp = A(x)
		A(x) = A(y)
		A(y) = tmp
	}
	val n = readInt()
	val A = (0 until n).map { _ => readInt() }.toArray
	var Array(x, y) = readLine().split(' ').map { _.toInt - 1 }
	swap(A, x, y)
	for (i <- 0 until n) println(A(i))
}
Swift
2変数の入れ替え
let ab = readLine()!.split(separator: " ").compactMap { Int($0) }
var (a, b) = (ab[0], ab[1])
(a, b) = (b, a)
print(a, b)
変数の入れ替え
let xy = readLine()!.split(separator: " ").compactMap { Int($0) }
var (x, y) = (xy[0], xy[1])
(x, y) = (y, x)
print(x, y)
配列の要素の入れ替え
let xyn = readLine()!.split(separator: " ").compactMap { Int($0) }
let (x, y, n) = (nxy[0] - 1, nxy[1] - 1, nxy[2])
var A = readLine()!.split(separator: " ").compactMap { Int($0) }
(A[x], A[y]) = (A[y], A[x])
for i in 0..<n {
	print(A[i])
}
指定要素の入れ替え
let n = Int(readLine()!)!
var A = (0..<n).map { _ in Int(readLine()!)! }
let xy = readLine()!.split(separator: " ").compactMap { Int($0) }
let (x, y) = (xy[0] - 1, xy[1] - 1)
(A[x], A[y]) = (A[y], A[x])
for i in 0..<n {
	print(A[i])
}
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