Question

我一直在编写我的大学，我们正在处理矩阵，我找不到代码中的错误，该错误正在改变我保存矩阵列的变量值。我已经尝试过调试它并且找不到它，它只是结束了我在矩阵中分配内存的函数，并输入了下一个函数（从键盘获取值来填充矩阵）的错误列值。代码是下一个：

#include <stdio.h>
#include <stdlib.h>
#define DEBUG 1

void allocate (int ***mat,int n,int m){
    int i;
    *mat = (int **) malloc (n*sizeof(int*));
    for (i=0; i<n; i++){
        mat[i] = (int *) malloc (m*sizeof(int));
    }
    #if DEBUG
        printf ("allocate n: %d m: %d\n",n,m);
    #endif // DEBUG
}

void initialize (int **mat, int n, int m){
    int i,j;
    #if DEBUG
        printf ("initialize n: %d m: %d\n",n,m);
    #endif // DEBUG
    for (i=0; i<n; i++){
        for (j=0; j<m; j++){
            printf ("Enter value for position [%d][%d]: ",i,j);
            scanf ("%d",&(mat[i][j]));
        }
    }
}

int main()
{
        int n=2;
        int m=3;
        int **mat=NULL;
        #if DEBUG
            printf ("before allocate n: %d m: %d\n",n,m);
        #endif // DEBUG
        allocate (&mat,n,m);
         #if DEBUG
            printf ("after allocate n: %d m: %d\n",n,m);
        #endif // DEBUG
        initialize (mat,n,m);
        return 0;
}

因此，如果在DEBUG设置为1的情况下运行此操作，您将获得n和m的值（这是我的行和列）。我正在使用代码块。谢谢你的时间！

Answer 1

更新功能

---
name: home
url: /
---

<div ng-controller="MainCtrl">
    <header>
        <p class="sponsored" id="top">Sponsored by </p>
        <img src="http://placehold.it/200x30" class="sponsors" alt="">
        <h1>Business Directory</h1>
        <div class="find">
            <input type="search" placeholder="What are you looking for?" ng-model="query">
        </div><!-- /.find -->
    </header>

    <div class="businesses">
        <div class="storeIcon">
            <img src="/assets/img/store.png" class="store" alt="">
        </div><!-- /.storeIcon -->

        <p class="number">Search {{businesses.length}} businesses in Brandon</p><button class="filter button">Filter by <i class="fa fa-chevron-down"></i></button>
        <div class="options">
            <div class="cat">
                <div class="categories">
                    <div class="group">
                        <p class="name">Grade Level</p>
                        <div class="check">
                            <input type="radio" name=""><p>Auto</p>
                            <input type="checkbox" name=""><p>Restaurant</p>
                            <input type="checkbox" name=""><p>Other</p>
                        </div><!-- /.check -->
                    </div><!-- /.group -->

                    <div class="group">
                        <p class="name">School Type</p>
                        <div class="check">
                            <input type="checkbox">
                            <input type="checkbox">
                            <input type="checkbox">
                            <input type="checkbox">
                            <input type="checkbox">
                        </div><!-- /.check -->
                    </div><!-- /.group -->
                </div><!-- /.categories -->
            </div><!-- /.cat -->
        </div><!-- /.options -->
    </div><!-- /.businesses -->



    <div class="all">
        <div class="business large-4.columns" data-ng-repeat="business in businesses | filter:query | orderBy:'name'" >
            <div class="overlay">
                <a href=""><img src="http://placehold.it/300x300" class="storefront" alt=""></a>
            </div><!-- /.overlay -->
            <div class="info">
                <a href=""><p class="name">{{business.name}}</p></a>
                <p class="description">{{business.description}}</p>
                <p class="address">{{business.address}}</p>
                <a href="" class="website">{{business.website}}</a>
            </div><!-- /.info -->
        </div>
    </div>

    <footer>
    <hr>
        <i class="fa fa-twitter"></i>
        <i class="fa fa-facebook"></i>

    <div class="backContainer">
        <a href="#top"><p class="back">Back to top</p></a>
    </div><!-- /.backContainer -->
    </footer>
</div>

Answer 2

http://coliru.stacked-crooked.com/a/4d3cb5ed16ae73a5

// add item to cart on visit depending on cart total value
add_action( 'init', 'add_product_to_cart' );

function add_product_to_cart() {
  if ( isset($_POST['mix']) && !empty($_POST['mix']) && isset($_POST['mix_name']) && !empty($_POST['mix_name']) ) {
    global $woocommerce;    

      $addcart = $woocommerce->cart->add_to_cart( $product_ID = 700,  $quantity=1, $variation_id= '', array('attribute_strain' => 'sativa', 'attribute_level' => 'cbd', 'attribute_flavor' => 'flower shop') );   

      foreach ($woocommerce->cart->cart_contents as $cart_item_key => $values) {
            $_product = $values['data'];
          //find all simple product type to remove
          if($_product->product_type == 'simple') {
             unset($woocommerce->cart->cart_contents[$cart_item_key]);
          }
      }

    if($addcart) {
            wp_safe_redirect( WC()->cart->get_checkout_url() );
            exit;
        } else {
            wc_print_notices();
            _e('Can\'t add');
        }  
  }
}

您看，实际上您没有使用void allocate (int ***mat,int n,int m){ int i; *mat = (int **) malloc (n*sizeof(int*)); for (i=0; i<n; i++){ //This is where the error is. (*mat)[i] = (int *) malloc (m*sizeof(int)); } #if DEBUG printf ("allocate n: %d m: %d\n",n,m); #endif // DEBUG }引用数组中的特定单元格。不，您实际引用了指向矩阵的指针，然后将其索引到列或行，这意味着您为mat[i]分配了内存，而不是int*。

因此，您需要将原始矩阵指针与矩阵相关联，然后索引 - ＆gt; int。

从C中的函数返回后变量值发生变化

2 个答案: