我已經成功地爲輸入文件建立了一個鄰接矩陣,輸入的第一行是頂點的總數,下面幾行是以任意順序作爲頂點對的邊。例如如何從鄰接矩陣建立鄰接表?
file.txt的
7
1 2
4 6
4 3
5 2
然而,當我運行這個程序,鄰接矩陣構建成功,但是當我嘗試創建一個鄰接表的結構樹的陣列,程序Seg故障(核心轉儲)。 關於爲什麼程序失敗的任何線索?有問題的功能是:
tree * buildAdjList(int a[][100], int n)
{ int i, j, k;
tree *node;
tree * adjArray[n];
for(i=0; i<=n; i++)
adjArray[i] = NULL;
for(j=0; j<=n; j++)
for(k=0; k<=n; k++)
if(a[j][k] == 1){
node = (tree *)malloc(sizeof(tree));
node->val = k;
node->next = adjArray[j];
adjArray[j] = node;
}
return adjArray[0];
}
和程序的其餘部分:
#include <stdio.h>
#include <stdlib.h>
struct tree{
int val;
struct tree *next;
};
typedef struct tree tree;
void printArray(int a[][100],int n);
void adjacencyMatrix(int a[][100], int n, int p1, int p2, FILE * inputF);
tree * buildAdjList(int a[][100], int n);
void printAdjArray(tree * adjArr[], int n);
int main(int argc, char ** argv)
{
int a[100][100];
int n,*q;
FILE * inputFile;
int entries, i;
inputFile = fopen(argv[1], "r");
int p1, p2 =0;
if(inputFile==NULL){
printf("File failed to open.");
exit(EXIT_FAILURE);
}
fscanf(inputFile, "%d", &entries);
tree * adjarray[entries];
q = (int *)malloc(sizeof(int)*n);
adjacencyMatrix(a,entries,p1,p2,inputFile);
adjarray[0] = buildAdjList(a, entries);
printAdjArray(adjarray, entries);
return 0;
}
void adjacencyMatrix(int a[][100], int n, int p1, int p2, FILE * inputF){
int i,j;
do{
for(i = 0;i <= n; i++)
{
for(j = 0;j <=n; j++)
{ if(i==p1 && j == p2){
a[i][j] = 1;
a[j][i] = 1;
}
}
a[i][i] = 0;
}
}while(fscanf(inputF, "%d %d", &p1, &p2) !=EOF);
printArray(a,n);
}
任何及所有的幫助深表感謝:)