雙指針結構內結構

我怎樣才能訪問一個結構指針雙指針？與代碼波紋管，調用addBow（）給我一個分段故障（核心轉儲）錯誤雙指針結構內結構

typedef struct 
{ 
    int size; 
    tCity **cities; 

}tGraph; 

//para iniciar el grafo 
void initGraph(tGraph *graph, int size) 
{ 
    graph = (tGraph*)malloc(sizeof(tGraph)); 
    graph->cities = (tCity**)malloc(sizeof(tCity*) * size); 
    graph->size = size; 
} 

//agrega un arco entre ciudades 
void addBow(tGraph *graph, int id, tCity *city) 
{ 
    if (graph->cities[id] == NULL) 
    {  
     graph->cities[id] = city; 
    } 
    else 
    { 
     tCity *cur = graph->cities[id]; 
     while (getNext(cur) != NULL) 
     { 
      cur = getNext(cur); 
     } 
     setNext(cur, city); 
    } 
}

其是用於graph->城市[ID]的正確語法??

感謝

SOLUTION：編輯initGraph解決問題，因爲內存沒有被分配

tGraph* initGraph(int size) 
{ 
    tGraph *graph = (tGraph*)malloc(sizeof(tGraph)); 
    graph->cities = (tCity**)malloc(sizeof(tCity*) * size); 
    graph->size = size; 
    return graph; 
}

來源

2013-08-31 JoseMiguel

您應該有initGraph（）取（**圖）或返回的圖形。由於圖的malloc地址是initGraph的本地地址。

喜歡的東西：

void initGraph(tGraph **graph, int size) 
{ 
    tgraph *temp; 
    temp = (tGraph*)malloc(sizeof(tGraph*)); 
    temp->cities = (tCity**)malloc(sizeof(tCity*) * size); 
    temp->size = size; 
    *graph = temp; 
}

來源

2013-08-31 22:03:12

他在那裏存儲指針。 – Inspired

@靈感。同意。更新了答案 –

@ManojPandey Thaanks，解決它，更新。 – JoseMiguel

graph = (tGraph*)malloc(sizeof(tGraph*));

還有就是你的問題之一...... 應該 graph = malloc(sizeof(tGraph));

來源

2013-08-31 22:05:07

這是一個問題，但我認爲崩潰現在是由'initGraph'將內存分配給調用者傳遞的指針副本引起的。即分配到一旦泄漏功能返回 – simonc

@simonc良好的電話我沒有認識到這一點泄漏。 –

製作initGraph()返回一個指向tGraph。

tGraph* initGraph(int size) { 

tGraph* graph; 

graph = malloc(sizeof(tGraph)); 
graph->cities = malloc(sizeof(tCity*) * size); 
graph->size = size; 

return graph; 
}

來源

2013-08-31 22:40:48 verbose

雙指針結構內結構

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