Leer 2 matrices e intercambiar valores
import java.util.*;
public class problema1{
public static void main (){
int a[][] = new int[3][3];
int b[][] = new int[3][3];
int x[][] = new int[3][3];
int i,j;
Scanner teclado = new Scanner (System.in);
System.out.println("Escribe los valores de la matriz A");
for (i=0; i<3;i++){
for (j=0; j<3;j++){
System.out.print( i +","+ j +": " );
a [i][j] = teclado.nextInt();
}
}
System.out.println("Matriz A completa");
System.out.println("");
System.out.println("Escribe los valores de la matriz B");
for (i=0; i<3;i++){
for (j=0; j<3;j++){
System.out.print(i +","+ j+ ": ");
b [i][j] = teclado.nextInt();
}
}
for (i=0; i<3;i++){
for (j=0; j<3;j++){
x [i][j] = b [i][j];
b [i][j] = a [i][j];
a [i][j] = x [i][j];
}
}
}
}