Sum line in matrix

Question

I implemented this code to sum line by row of the matrix and tell which row has the highest sum, but the output is blank, in which case the sum would be line 1 (1+1+1+1) line 2 (0+1+0+1) and so on. someone can help me?

  <?php
  $matriz = array
  (
   array(1, 0, 0, 1),
   array(1, 1, 1, 0),
   array(1, 0, 1, 1),
   array(1, 1, 1, 1)
 );
 $sum = 0;
 $no = 0;
 foreach ($matriz as $array){
    if(($sum += $array[$no])>$sum+=$array[$no+1]){
        echo "a linha de maior soma é =  $array[no]";
    }
 }
?>


 

Answer 1

Try this:

<?php

$matriz = array(
    array(1, 10, 3, 50),
    array(1, 10, 3, 50),
    array(1, 10, 3, 50),
    array(1, 10, 3, 50),
    array(1, 10, 3, 50)
);

$num_lines = count($matriz);
$num_elem_per_line = count($matriz[0]);
$maior = 0;
$maiorSoma = 0;
$soma = 0;

// Linha
for( $linha = 0; $linha <= ($num_elem_per_line-1); $linha++ ) {
    // Coluna
    for( $coluna = 0; $coluna <= ($num_lines-1); $coluna++ ) {    
        // Soma os elementos da linha
        $soma += $matriz[$coluna][$linha];
    }
    // verifica se a soma atual é maior que a maior soma já registrada
    if ( $soma > $maiorSoma ) {
        $maior = $linha+1; // $linha é indice, logo, começa por 0, por isso +1
        $maiorSoma = $soma;
    }
    // Reinicia a soma da soma para zero
    $soma = 0;
}

echo "A linha de maior soma é: $maior <br>";
echo "A maior soma é: $maiorSoma";
?>

---

The algorithm will not accept that a next column is the largest sum if it has the same amount of elements, as in the following example:

$matriz = array(
    array(1, 10, 3, 5, 10),
    array(1, 10, 3, 5, 10),
    array(1, 10, 3, 5, 10),
    array(1, 10, 3, 5, 10),
    array(1, 10, 3, 5, 10)
);

In this case, the algorithm will point out that the longest line is the second. To change that, just put >= there in the IF

---

Only works with matrices that have all columns with equal amount of elements

Does not work in the following example:

$matriz = array(
    array(1, 10, 3, 50, 100),
    array(1, 10, 3, 50),
    array(1, 10, 3, 50),
    array(1, 10, 3, 50),
    array(1, 10, 3, 50)
);