Dada una array 2D arr[][] de tamaño M x N enteros donde M es el número de filas y N es el número de columnas. La tarea es invertir cada fila de la array 2D dada.
Ejemplo:
Input: arr[][] =
{ {1, 2, 3},
{4, 5, 6},
{7, 8, 9} }
Output:
3 2 1
6 5 4
9 8 7
Input: arr[][] =
{ {1, 2},
{4, 5},
{7, 8},
{9, 10} }
Output:
2 1
5 4
8 7
10 9
Acercarse:
- Para cada fila en la array 2D dada, haga lo siguiente:
- Inicialice el índice de inicio como 0 y el índice final como N-1.
- Iterar el ciclo hasta que el índice de inicio sea menor que el índice final, intercambiar el valor en estos índices y actualizar el índice como:
swap(arr[i][start], arr[i][end]) start++; end--;
- Realice la operación anterior para todas las filas de la array 2D.
A continuación se muestra la implementación del enfoque anterior:
C++
// C++ implementation of the above approach
#include <bits/stdc++.h>
using namespace std;
const int M = 3;
const int N = 3;
// A utility function
// to swap the two element
void swap(int* a, int* b)
{
int temp = *a;
*a = *b;
*b = temp;
}
// Function to reverse
// the given 2D arr[][]
void reverseArray(int arr[M][N])
{
// Traverse each row of arr[][]
for (int i = 0; i < M; i++) {
// Initialise start and end index
int start = 0;
int end = N - 1;
// Till start < end, swap the element
// at start and end index
while (start < end) {
// Swap the element
swap(&arr[i][start],
&arr[i][end]);
// Increment start and decrement
// end for next pair of swapping
start++;
end--;
}
}
// Print the arr[][] after
// reversing every row
for (int i = 0; i < M; i++) {
for (int j = 0; j < N; j++) {
cout << arr[i][j] << ' ';
}
cout << endl;
}
}
// Driver Code
int main()
{
int arr[][3] = { { 1, 2, 3 },
{ 4, 5, 6 },
{ 7, 8, 9 } };
// Function call
reverseArray(arr);
return 0;
}
Java
// Java implementation of the above approach
class GFG{
static int M = 3;
static int N = 3;
// Function to reverse
// the given 2D arr[][]
static void reverseArray(int arr[][])
{
// Traverse each row of arr[][]
for (int i = 0; i < M; i++) {
// Initialise start and end index
int start = 0;
int end = N - 1;
// Till start < end, swap the element
// at start and end index
while (start < end) {
// Swap the element
int temp = arr[i][start];
arr[i][start] = arr[i][end];
arr[i][end] = temp;
// Increment start and decrement
// end for next pair of swapping
start++;
end--;
}
}
// Print the arr[][] after
// reversing every row
for (int i = 0; i < M; i++) {
for (int j = 0; j < N; j++) {
System.out.print(arr[i][j] + " ");
}
System.out.println();
}
}
// Driver Code
public static void main(String[] args)
{
int arr[][] = { { 1, 2, 3 },
{ 4, 5, 6 },
{ 7, 8, 9 } };
// Function call
reverseArray(arr);
}
}
// This code is contributed by PrinciRaj1992
Python3
# Python3 implementation of the above approach M = 3;N = 3; # Function to reverse # the given 2D arr[][] def reverseArray(arr) : # Traverse each row of arr[][] for i in range(M) : # Initialise start and end index start = 0; end = N - 1; # Till start < end, swap the element # at start and end index while (start < end) : # Swap the element arr[i][start], arr[i][end] = arr[i][end], arr[i][start]; # Increment start and decrement # end for next pair of swapping start += 1; end -= 1; # Print the arr[][] after # reversing every row for i in range(M) : for j in range(N) : print(arr[i][j],end= ' '); print(); # Driver Code if __name__ == "__main__" : arr = [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ] ]; # Function call reverseArray(arr); # This code is contributed by AnkitRai01
C#
// C# implementation of the above approach
using System;
class GFG{
static int M = 3;
static int N = 3;
// Function to reverse
// the given 2D [,]arr
static void reverseArray(int [,]arr)
{
// Traverse each row of [,]arr
for (int i = 0; i < M; i++) {
// Initialise start and end index
int start = 0;
int end = N - 1;
// Till start < end, swap the element
// at start and end index
while (start < end) {
// Swap the element
int temp = arr[i,start];
arr[i, start] = arr[i, end];
arr[i, end] = temp;
// Increment start and decrement
// end for next pair of swapping
start++;
end--;
}
}
// Print the [,]arr after
// reversing every row
for (int i = 0; i < M; i++) {
for (int j = 0; j < N; j++) {
Console.Write(arr[i, j] + " ");
}
Console.WriteLine();
}
}
// Driver Code
public static void Main(String[] args)
{
int [,]arr = { { 1, 2, 3 },
{ 4, 5, 6 },
{ 7, 8, 9 } };
// Function call
reverseArray(arr);
}
}
// This code is contributed by PrinciRaj1992
Javascript
<script>
// JavaScript implementation of the above approach
const M = 3;
const N = 3;
// Function to reverse
// the given 2D arr
function reverseArray(arr) {
// Traverse each row of arr
for (i = 0; i < M; i++) {
// Initialise start and end index
var start = 0;
var end = N - 1;
// Till start < end, swap the element
// at start and end index
while (start < end) {
// Swap the element
var temp = arr[i][start];
arr[i][start] = arr[i][end];
arr[i][end] = temp;
// Increment start and decrement
// end for next pair of swapping
start++;
end--;
}
}
// Print the arr after
// reversing every row
for (i = 0; i < M; i++) {
for (j = 0; j < N; j++) {
document.write(arr[i][j] + " ");
}
document.write("<br/>");
}
}
// Driver Code
var arr = [ [ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7, 8, 9 ] ];
// Function call
reverseArray(arr);
// This code is contributed by todaysgaurav
</script>
Producción:
3 2 1 6 5 4 9 8 7
Publicación traducida automáticamente
Artículo escrito por ritikadhamija y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA