我正在尝试在无向图中插入节点,在第一次插入时,代码效果很好,但是在第二次,代码不再起作用,我也不明白为什么。有人可以帮我解决这个问题吗?
我已经尝试在Dev-c ++中进行编译,有时可以运行代码,而其他人则不能,但在CodeBlocks和CMD(Windows)中则无法工作。
这是我的代码:
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <malloc.h>
typedef struct tedge {
int vdest; //destiny vertex
double weight;
struct tedge* next;
}TypeEdge;
typedef TypeEdge* TypePointer;
typedef struct {
TypePointer* listAdj;
int numVertex;
int numEdges;
}TypeGraph;
//initialize the graph
bool initializeGraph(int nv, TypeGraph* graph) {
if(nv <= 0) return false;
int i;
if(graph->listAdj = (TypePointer*)malloc(nv*sizeof(TypePointer))) {
graph->numEdges = 0;
graph->numVertex = nv;
for(i = 0; i < nv; i++)
graph->listAdj[i] = NULL;
return true;
}
return false;
}
//insertion
bool insertEdge(int v1, int v2, double weight, TypeGraph *graph) {
if(!graph) return false;
if((v1 < 0) || (v1 >= graph->numVertex)) return false;
if((v2 < 0) || (v2 >= graph->numVertex)) return false;
TypePointer new = (TypePointer)malloc(sizeof(TypePointer));
new->vdest = v2;
new->weight = weight;
new->next = graph->listAdj[v1];
graph->listAdj[v1] = new;
TypePointer simetry = (TypePointer)malloc(sizeof(TypePointer));
simetry->vdest = v1;
simetry->weight = weight;
simetry->next = graph->listAdj[v2];
graph->listAdj[v2] = simetry;
graph->numEdges++;
return true;
}
void printGraph(TypeGraph* graph) {
int i;
for(i = 0; i < graph->numVertex; i++) {
TypePointer actual = graph->listAdj[i];
printf("v %i: ", i);
while(actual != NULL) {
printf("(adj %i, weight %g); ", actual->vdest, actual->weight);
actual = actual->next;
}
printf("\n");
}
}
int main() {
TypeGraph graph;
initializeGraph(9, &graph);
insertEdge(0, 1, 8, &graph);
insertEdge(0, 3, 4, &graph);
insertEdge(0, 6, 11, &graph);
insertEdge(1, 2, 7, &graph);
insertEdge(1, 4, 2, &graph);
insertEdge(1, 8, 4, &graph);
insertEdge(2, 5, 9, &graph);
insertEdge(2, 8, 14, &graph);
insertEdge(3, 6, 8, &graph);
insertEdge(4, 6, 7, &graph);
insertEdge(5, 8, 10, &graph);
insertEdge(6, 7, 1, &graph);
insertEdge(7, 8, 2, &graph);
printGraph(&graph);
return 0;
}
如果有人可以帮助我,我将接受任何建议。谢谢。
最佳答案
请参阅带有指针的typedef中的危险
TypePointer new = (TypePointer)malloc(sizeof(TypePointer));
new->vdest = v2;
new->weight = weight;
new->next = graph->listAdj[v1];
这只会为指针分配足够的内存。我会建议
TypePointer new = malloc(sizeof(*new));
也在这里
TypePointer simetry = (TypePointer)malloc(sizeof(TypePointer));
应该是
TypePointer simetry = malloc(sizeof(*simetry));
经过更正后,该程序报告:
v 0 :(调整6,权重11); (adj 3,权重4); (adj 1,权重8);
v 1:(adj 8,权重4); (adj 4,权重2); (adj 2,权重7); (adj 0,权重8);
v 2:(adj 8,重量14); (adj 5,权重9); (adj 1,权重7);
v 3:(adj 6,重量8); (adj 0,权重4);
v 4 :(调整6,权重7); (adj 1,权重2);
v 5 :(调整8,权重10); (adj 2,权重9);
v 6 :(调整7,权重1); (adj 4,权重7); (adj 3,权重8); (adj 0,权重11);
v 7 :(调整8,权重2); (adj 6,权重1);
v 8 :(调整7,权重2); (adj 5,权重10); (adj 2,权重14); (adj 1,权重4);
我也注意到这些函数返回一个状态,该状态将被忽略,尽管这并没有导致此处的崩溃。