我如何在下面的代码中解决我的问题 [英] How can I solve my problem in the below code

问题描述

#include <iostream>
using namespace std;
typedef struct node{
    public:
    struct node *column;
    bool flag;
    struct node *row;
    int ii,jj;
    union{
        int val;
        struct node *next;
    }u;
}nod,*ptr;
static ptr strt1;
static ptr strt2;
static ptr y;
int t;
int tt;

void AddLink(int i,int j){
    int count = 0;
    ptr q = strt2;
    ptr p = strt1;
    for (int k=0;k<i;k++){
        q = q->u.next;
    }
    for (int k=0;k<j;k++){
        p = p->u.next;
    }
    if (q->column==NULL && p->row==NULL){
        ptr m = (node *)malloc(sizeof(node));
        q->column = m;
        m->u.val = 1;
        m->column = q;
        m->ii = i;
        m->flag = false;
        p->row = m;
        m->row = p;
        m->jj= j;
        count =1;
    }
    if (q->column!=NULL && p->row ==NULL){
        ptr h=q;
        ptr w = q;
        q = q->column;
        while (q->jj<j&&q!=w){
            h =q;
            q = q->column;
        }
        ptr mm = (node *)malloc(sizeof(node));
        h->column = mm;
        mm->column = q;
        mm->ii = i;
        mm->u.val = 1;
        mm->flag = false;
        mm->jj = j;
        mm->row = p;
        count = 1;
        p->row = mm;
    }
    if (p->row!=NULL && q->column==NULL){
        ptr hh=p;
        ptr ww = p;
        p = p->row;
        while (p->ii<i&&p!=ww){
            hh =p;
            p = p->row;
        }
        ptr mmm = (node *)malloc(sizeof(node));
        hh->row = mmm;
        mmm->row = p;
        mmm->jj = j;
        mmm->u.val = 1;
        mmm->flag = false;
        mmm->ii = i;
        mmm->column = q;
        count = 1;
        q->column = mmm;
    }
    if (p->row!=NULL && q->column!=NULL && count==0){
        ptr hhh = p;
        ptr www = p;
        ptr g = q;
        ptr gg = q;
        q = q->column;
        p = p->row;
        while (q->jj<j&&q!=gg){
            g =q;
            q = q->column;
        }
        while ((p->ii)<i&&p!=www){
            hhh =p;
            p = p->row;
        }
        if (q->jj!=j && p->ii!=i){
            ptr mmmm = (node *)malloc(sizeof(node));
            hhh->row = mmmm;
            mmmm->row = p;
            g->column = mmmm;
            mmmm->column = q;
            mmmm->flag = false;
            mmmm->u.val = 1;
            mmmm->ii = i;
            mmmm->jj = j;
        }
        else{
            p->u.val +=1;
        }
    }
}
void DeleteLink(int i,int j){
    ptr q = strt2;
    ptr p = strt1;
    for (int k=0;k<i;k++){
        q = q->u.next;
    }
    ptr w =q;
    ptr g = q;
    q = q->column;
    while (g->jj<j&&q!=w){

        q = g->column;
        if (q->jj==j){
            q->u.val-=1;
        }
        g=q;
    }
}
int RetrieveValue(int i,int j){
    ptr q = strt2;
    ptr p = strt1;
    int c = 0;
    for (int k=0;k<i;k++){
        q = q->u.next;
    }
    ptr w =q;
    ptr g = q;
    q = q->column;
    while (g->jj<j&&q!=w){

        q = g->column;
        if (q->jj==j){
            c = q->u.val;
        }
        g=q;
    }
    return c;
}
int RetrieveRowSumUptoKthColumn(int i,int j){
    ptr p = strt1;
    int c=0;
    for (int k=0;k<i;k++){
        p = p->u.next;
    }
    ptr w = p;
    p = p->row;
    while (p->ii<=j&&p!=w){
        c+=p->u.val;
        p = p->row;
    }
    return c;
}
int RetrieveColumnSumUptoKthRow(int i,int j){
    ptr q=strt2;
    int c=0;
    for (int k=0;k<i;k++){
        q= q->u.next;
    }
    ptr w = q;
    q = q->column;
    while (q->jj<=j &&q!=w){
        c+=q->u.val;
        q = q->column;
    }
    return c;
}
int m;
int n;
ptr a;
ptr b;
int main(){


    a = (node *)malloc(sizeof(node));
    b = (node *)malloc(sizeof(node));
    strt1 = a;
    strt2 = b;
    cout<<a->u.next;
    cout<<a->column;
    cout<<a->row;
    for(int i=0;i<10000000;i++){
        ptr ar =(node *) malloc(sizeof(node));
        ar->flag = true;
        ar->jj = i;
        a->u.next = ar;
        a = a->u.next;
    }
    a->u.next = strt1;
    for(int i=0;i<10000000;i++){
        ptr br =(node *) malloc(sizeof(node));
        br->ii = i;
        br->flag = true;
        b->u.next = br;
        b = b->u.next;
       
    }
    b->u.next = strt2;
    int e;
    int cc;
    cin>>cc;
    for(int i=0;i<cc;i++){
        
       
        cin>>e;
        cin>>m;
        cin>>n;
        if (e==1)
            AddLink(m,n);
        if (e==2)
            DeleteLink(m,n);
        if (e==3)
            cout<<RetrieveValue(m,n)<<endl;
        if (e==4)
            cout<<RetrieveRowSumUptoKthColumn(m,n)<<endl;
        if (e==5)
            cout<<RetrieveColumnSumUptoKthRow(m,n)<<endl;
    }    
}

我尝试过的事情:

在执行代码时，我在这里遇到分段错误.请解决此问题，即确切告诉我问题出在哪里.

What I have tried:

Here i am getting segmentation fault on executing the code.Please solve this problem i.e. tell me exactly where the problem is occuring.

推荐答案

查找导致seg的行故障需要调试您的应用程序.

但是，您的代码有三个大问题:

Finding the line that results in the seg fault requires debugging your application.

However, your code has three big problems:

1. 您尚未初始化分配的结构的成员
   
2. 您没有检查有效的指针(对于链接列表，使用NULL初始化指针并进行检查是必不可少的)
   
3. 您拥有一个联合身份，可以在其中以int
   身份访问struct node *next成员

1. You did not initialise the members of your allocated structures
   
2. You did not check for valid pointers (it is essential for linked lists to initialise pointers with NULL and check them)
   
3. You have a union where you can access the struct node *next member as int
   

特别是最后一个将在此行中创建一个无效的指针:

Especially the last one will create an invalid pointer in this line:

q->u.val-=1;

我的建议:

• 在分配后初始化所有结构成员，方法是将它们设置为零或使用calloc()而不是malloc()
  
• 使用它们之前，请检查结构中的所有指针是否为NULL
  
• 请勿使用此类联合
  


My suggestions:




• Initialise all struct members after allocation by setting them to zero or use calloc() instead of malloc()
  
• Check all pointers from the struct for being NULL before using them
  
• Don''t use such kinds of unions
  




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