问题描述
我用C语言编写了以下程序。
#include<stdio.h>
#include<stdlib.h>
struct stack{
int *arr;
int top;
};
struct stack* init(int size){
struct stack *s=NULL;
s=malloc(sizeof(struct stack));
s->arr=malloc(sizeof(int) * (size));
s->top=-1;
return s;
}
void push(struct stack* t,int val){
++(t->top);
t->arr[t->top]=val;
}
void pop(struct stack* t){
if(t->top != -1)
t->top--;
}
int peek(struct stack *t){
if(t->top != -1)
return t->arr[t->top];
return -1;
}
int isEmpty(struct stack *t){
if(t->top == -1)
return 1;
return 0;
}
int adjVisited(int n,int **g,int i){
for(int j=0;j<n;j++){
if(g[i][j] == 1)
return 0;
}
return 1;
}
void Euler(int v,int n,int e){
struct stack *temp=init(e+2);
struct stack *ans=init(e+2);
push(temp,v);
while(!isEmpty(temp)){
int u=peek(temp);
if(adjVisited(n,g,u)){
push(ans,u);
pop(temp);
}
else{
for(int j=0;j<n;j++){
if(g[u][j] == 1){
push(temp,j);
g[u][j] = 0;
g[j][u] = 0;
break;
}
}
}
}
free(temp->arr);
free(temp);
while(!isEmpty(ans)){
printf("%d ",peek(ans));
pop(ans);
}
}
void addEdge(int n,int** g,int u,int v){
g[u][v]=1;
g[v][u]=1;
}
int main(){
int n,e,x,y;
printf("Enter number of nodes in the graph\n");
scanf("%d",&n);
int **graph = (int **)calloc(n,sizeof(int *));
for (int i=0; i<n; i++)
graph[i] = (int *)calloc(n,sizeof(int));
printf("Enter number of edges in the graph\n");
scanf("%d",&e);
printf("Enter end vertices of the edge to be added\n");
while(e--){
scanf("%d %d",&x,&y);
addEdge(n,graph,y);
}
Euler(0,n,e);
for(int i=0;i<n;i++)
free(graph[i]);
free(graph);
return 0;
}
Valgrind向我抛出无效的写入和无效的读取错误。这是我第一次遇到此错误。据我了解，每当我想将数据写入尚未动态分配的内存位置时，就会发生这种情况。
==4199== Memcheck,a memory error detector
==4199== Copyright (C) 2002-2017,and GNU GPL'd,by Julian Seward et al.
==4199== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
==4199== Command: ./a.out
==4199==
Enter number of nodes in the graph
6
Enter number of edges in the graph
6
Enter end vertices of the edge to be added
0 1
1 2
2 3
3 4
4 5
5 0
==4199== Invalid write of size 4
==4199== at 0x109294: push (hier.c:31)
==4199== by 0x109477: Euler (hier.c:75)
==4199== by 0x1096D4: main (hier.c:114)
==4199== Address 0x4a52bc4 is 0 bytes after a block of size 4 alloc'd
==4199== at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==4199== by 0x10923E: init (hier.c:24)
==4199== by 0x1093AA: Euler (hier.c:60)
==4199== by 0x1096D4: main (hier.c:114)
==4199==
==4199== Invalid read of size 4
==4199== at 0x1092F4: peek (hier.c:41)
==4199== by 0x1093F2: Euler (hier.c:66)
==4199== by 0x1096D4: main (hier.c:114)
==4199== Address 0x4a52bc4 is 0 bytes after a block of size 4 alloc'd
==4199== at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==4199== by 0x10923E: init (hier.c:24)
==4199== by 0x1093AA: Euler (hier.c:60)
==4199== by 0x1096D4: main (hier.c:114)
==4199==
==4199== Invalid write of size 4
==4199== at 0x109294: push (hier.c:31)
==4199== by 0x10941E: Euler (hier.c:69)
==4199== by 0x1096D4: main (hier.c:114)
==4199== Address 0x4a52c64 is 0 bytes after a block of size 4 alloc'd
==4199== at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==4199== by 0x10923E: init (hier.c:24)
==4199== by 0x1093CC: Euler (hier.c:62)
==4199== by 0x1096D4: main (hier.c:114)
==4199==
==4199== Invalid read of size 4
==4199== at 0x1092F4: peek (hier.c:41)
==4199== by 0x10951A: Euler (hier.c:86)
==4199== by 0x1096D4: main (hier.c:114)
==4199== Address 0x4a52c78 is 20 bytes after a block of size 4 alloc'd
==4199== at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==4199== by 0x10923E: init (hier.c:24)
==4199== by 0x1093CC: Euler (hier.c:62)
==4199== by 0x1096D4: main (hier.c:114)
==4199==
编辑：测试以下输入时出现此错误
6 as number of vertices
9 as number of edges
0 1
1 2
2 3
3 4
4 5
5 0
0 2
2 4
0 4 as the edges of the graph
有人可以帮助我解决此错误吗？
解决方法
暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！
如果你已经找到好的解决方法，欢迎将解决方案带上本链接一起发送给小编。
小编邮箱:dio#foxmail.com (将#修改为@）