Предлагаю разбить задачу на 4 этапа: чтение текста, построение массива строковых ячеек, построение массива целочисленных матриц, произведение матриц:
import java.util.ArrayList;
import java.util.List;
public class MatrixMul {
static String[][] text2StrMatrices( String[] text ) {
List< String[] > w = new ArrayList<>( 12 );
for( String line : text )
{
List< String > l = new ArrayList<>( line.length() / 2 );
for( int i = 0; i < line.length(); ++i )
{
char c = line.charAt( i );
if( c == ' ' )
{
l.add( " " );
++i;
}
else {
String num = "";
while( c != ' ' && i < line.length()) {
num += c;
if( ++i < line.length()) {
c = line.charAt( i );
}
}
l.add( num );
}
}
w.add( l.toArray( new String[l.size()]));
}
return w.toArray( new String[w.size()][] );
}
static int countValues( String[] row )
{
int count = 0;
for( String value : row ) {
if( value.trim().length() > 0 ) {
++count;
}
}
return count;
}
static int[][][] strMatrices2IntegerMatrices( String[][] str ) {
int count = str[0].length;
int row = 0;
while( row < str.length && count == countValues( str[row] )) {
++row;
}
int first = -1;
for( int i = 0; first == -1 && i < str[row].length; ++i ) {
if( str[row][i].trim().length() > 0 ) {
first = i;
}
}
int columns = 0;
if( first > 0 ) {
columns = first;
}
else {
columns = countValues( str[row] );
}
List<int[]> w = new ArrayList<>(4);
for( int r = 0; r < ( first == 0 ? str.length : row ); ++r )
{
int[] aRow = new int[columns];
for( int c = 0; c < columns; ++c ) {
aRow[c] = Integer.parseInt( str[r][c] );
}
w.add( aRow );
}
int[][][] result = new int[2][][];
result[0] = w.toArray( new int[w.size()][] );
w.clear();
for( int r = 0; r < ( first == 0 ? row : str.length ); ++r )
{
int[] aRow = new int[str[0].length-columns];
for( int c = columns; c < str[r].length; ++c ) {
aRow[c-columns] = Integer.parseInt( str[r][c] );
}
w.add( aRow );
}
result[1] = w.toArray( new int[w.size()][] );
return result;
}
private static int[][] matricesProduct( int[][] a, int[][] b )
{
int m = a.length;
int n = b[0].length;
int p = b.length;
assert ( m == n ) || ( a[0].length == p ): "Incompatible dimensions";
int[][] prod = null;
if( p > -1 ) {
prod = new int[m][n];
for( int i = 0; i < m; ++i ) {
for( int j = 0; j < n; ++j ) {
for( int k = 0; k < p; ++k ) {
prod[i][j] += a[i][k] * b[k][j];
}
}
}
}
return prod;
}
static void test(
String title,
String[] text,
String[][] expectedStrMatrices,
int[][][] expectedMatrices,
int[][] expectedProduct )
{
System.out.println( title );
final String[][] observedStrMatrices = text2StrMatrices( text );
assert compare( expectedStrMatrices, observedStrMatrices ):
"text2StrMatrices() failed";
final int[][][] observedMatrices =
strMatrices2IntegerMatrices( observedStrMatrices );
assert compare( expectedMatrices, observedMatrices ):
"strMatrices2IntegerMatrices() failed";
final int[][] observedProduct =
matricesProduct( observedMatrices[0], observedMatrices[1] );
displayMatrix( observedProduct );
assert compare( expectedProduct, observedProduct ):
"matricesProduct() failed";
}
public static void main( String[] args ) {
final String[] text1 = {
"1 2 1 2 3",
"3 4 4 5 6",
"5 6",
"7 8",
};
final String[][] expectedStrMatrices1 = {
{ "1", "2", "1", "2", "3" },
{ "3", "4", "4", "5", "6" },
{ "5", "6" },
{ "7", "8" },
};
final int[][][] expectedMatrices1 = {{
{ 1, 2 },
{ 3, 4 },
{ 5, 6 },
{ 7, 8 },
},{
{ 1, 2, 3 },
{ 4, 5, 6 },
}};
final int[][] expectedProduct1 = {
{ 9, 12, 15 },
{ 19, 26, 33 },
{ 29, 40, 51 },
{ 39, 54, 69 },
};
test( "First test case", text1, expectedStrMatrices1, expectedMatrices1, expectedProduct1 );
final String[] text2 = {
"1 2 1 2 3",
"3 4 4 5 6",
" 7 8",
};
final String[][] expectedStrMatrices2 = {
{ "1", "2", "1", "2", "3" },
{ "3", "4", "4", "5", "6" },
{ " ", " ", " ", "7", "8" },
};
final int[][][] expectedMatrices2 = {{
{ 1, 2, 1 },
{ 3, 4, 4 },
},{
{ 2, 3 },
{ 5, 6 },
{ 7, 8 },
}};
final int[][] expectedProduct2 = {
{ 19, 23 },
{ 54, 65 },
};
test( "Second test case", text2, expectedStrMatrices2, expectedMatrices2, expectedProduct2 );
}// void main( String[] args )
private static void displayMatrix( int[][] matrix ) {
for( int i = 0; i < matrix.length; ++i ) {
for( int j = 0; j < matrix[i].length; ++j ) {
System.out.printf( "%2d ", matrix[i][j] );
}
System.out.println();
}
}
static boolean compare( String[][] left, String[][] right ) {
if( left.length != right.length ) {
return false;
}
for( int i = 0; i < left.length; ++i ) {
if( left[i].length != right[i].length ) {
return false;
}
for( int j = 0; j < left[i].length; ++j ) {
if( ! left[i][j].equals( right[i][j] )) {
return false;
}
}
}
return true;
}
static boolean compare( int[][][] left, int[][][] right ) {
if( left.length != right.length ) {
return false;
}
for( int i = 0; i < left.length; ++i ) {
if( left[i].length != right[i].length ) {
return false;
}
for( int j = 0; j < left[i].length; ++j ) {
if( left[i][j].length != right[i][j].length ) {
return false;
}
for( int k = 0; k < left[i][j].length; ++k ) {
if( left[i][j][k] != right[i][j][k] ) {
return false;
}
}
}
}
return true;
}
private static boolean compare( int[][] left, int[][] right )
{
if( left.length != right.length ) {
return false;
}
for( int i = 0; i < left.length; ++i ) {
if( left[i].length != right[i].length ) {
return false;
}
for( int j = 0; j < left[i].length; ++j ) {
if( left[i][j] != right[i][j] ) {
return false;
}
}
}
return true;
}
}
person
Aubin
schedule
14.11.2012
