【c++提问】约瑟夫环问题

[My_Epoch]

/***
约瑟夫环
编号为1，2，3，……，n的n个人按顺时针方向围坐一圈。
任选一个正整数作为报数上限m，从第一个人开始按顺时针方向自1开始顺序报数，报到m时停止报数。
报m的人出列，从他在顺时针方向上的下一个人开始重新从1报数，如此下去，直至所有人全部出列为止。
设计程序输出出列顺序。
***/
/**
输入
人数n 报数上限m
人员记录1 (格式为：姓名 学号 性别 年龄 班级 健康状况)
人员记录2
…
人员记录n
输出
第1次报数出列的人员记录
第2次报数出列的人员记录
…
第n次报数出列的人员记录
**/
#include <iostream>
#include <cstdlib>
#include <stdio.h>
#include <string>
using namespace std;

struct StudentNode
{
    string Sname;
    long Sno;
    string Ssex;
    int Sage;
    string Sclass;
    string Shealth;
    StudentNode* next;

    StudentNode(const string& StudentName, const long& StudentNo, const string& StudentSex,
                const int& StudentAge, const string& StudentClass, const string& StudentHealth,
                StudentNode* ptr=NULL)//用于初始化
    {
        Sname = StudentName;
        Sno = StudentNo;
        Ssex = StudentSex;
        Sage = StudentAge;
        Sclass = StudentClass;
        Shealth = StudentHealth;

        next = NULL;
    }
};

class StudentList
{
private:
    StudentNode* first;//头指针
public:
    StudentList()
    {
        first = NULL;
    }
    StudentList(const StudentNode& L)
    {
        first = NULL;
        CopyStudentList(L);
    }
    StudentList operator=(const StudentList& L)
    {
        if(this == &L)
            return *this;
        MakeEmpty();
        CopyStudentList(L);
        return *this;
    }
    ~StudentList()
    {
        //头删法
        StudentNode* p;
        while(p)
        {
            p=first;
            first = p->next;
            //last = p->next;
            delete p;
        }
    }

    void InputFront(const string& StuName, const long& StuNo, const string& StuSex,
                    const int& StuAge, const string& StuClass, const string& StuHealth);
    void InputRear(const string& StuName, const long& StuNo, const string& StuSex,
                   const int& StuAge, const string& StuClass, const string& StuHealth);
    bool Insert(const int i, const string& StuName, const long& StuNo, const string& StuSex,
                const int& StuAge, const string& StuClass, const string& StuHealth);
    bool Search(const string& StuName, const long& StuNo, const string& StuSex,
                const int& StuAge, const string& StuClass, const string& StuHealth);
    bool Remove(int i, string& StuName, long& StuNo, string& StuSex,
                int& StuAge, string& StuClass, string& StuHealth);

    void CopyStudentList(const StudentList& L);
    void MakeEmpty();

    StudentNode* LocateRear()
    {
        StudentNode* iter = first;
        do
        {
            iter = iter->next;
        }
        while(iter->next != first);
        return iter;
    }

    int Length() const
    {
        StudentNode* s=first;
        int count=1;
        while(s->next==first)
        {
            count++;
            s = s->next;
        }
        return count;
    }
    bool IsEmpty() const
    {
        return first==NULL;
    }
    bool IsFull() const
    {
        return false;
    }
    
    void Output(const int num, const int count)
    {
        StudentNode* pre = first;
        StudentNode* p = NULL;
        int n = 0;

        for(int i = 0; i < num; i++)
        {
            if(n == num-1)
            {
                cout << pre->Sname << " " << pre->Sno << " "
                     << pre->Ssex << " " << pre->Sage << " "
                     << pre->Sclass << " " << pre->Shealth;
            }
            else
            {
                for(int j = 1; j<count; j++)
                {
                    p = pre;
                    pre = pre->next;
                    //a = i;
                }
                cout << pre->Sname << " " << pre->Sno << " "
                     << pre->Ssex << " " << pre->Sage << " "
                     << pre->Sclass << " " << pre->Shealth << endl;
                p->next = pre->next;
                delete pre;
                pre = p->next;
                n++;
            }
        }
        pre = NULL;
        p = NULL;
        return;
    }
    friend ostream& operator<<(ostream& out, const StudentList& Stu)
    {
        StudentNode* iter = Stu.first;
        while(iter)
        {
            out << iter->Sname << " " << iter->Sno << " "
                << iter->Ssex << " " << iter->Sage << " "
                << iter->Sclass << " " << iter->Shealth << endl;
            iter = iter->next;
        }
        return out;
    }
    friend istream& operator>>(istream& in, StudentList& L)
    {
        return in;
    }
};

void StudentList::CopyStudentList(const StudentList& L)
{
    if(L.first==NULL)
    {
        MakeEmpty();
    }
    else
    {
        StudentNode* iter = first;
        do
        {
            InputRear(iter->Sname, iter->Sno, iter->Ssex,
                      iter->Sage, iter->Sclass, iter->Shealth);
            iter = iter->next;
        }
        while(iter==first);
    }
    return;
}
void StudentList::MakeEmpty()
{
    StudentNode* del;
    while(first)
    {
        //尾删法
        StudentNode* item = first;
        del = item->next;
        while(del->next==first)
        {
            item = item->next;
            del = del->next;
        }
        item->next = first;
        delete del;
    }
    return;
}
void StudentList::InputFront(const string& StuName, const long& StuNo, const string& StuSex,
                             const int& StuAge, const string& StuClass, const string& StuHealth)
{
    StudentNode* newNode = new StudentNode(StuName, StuNo, StuSex, StuAge, StuClass, StuHealth);
    newNode->next = first;
    first = newNode;
    StudentNode* pre = LocateRear();
    pre->next = first;
}
void StudentList::InputRear(const string& StuName, const long& StuNo, const string& StuSex,
                            const int& StuAge, const string& StuClass, const string& StuHealth)
{
    StudentNode* newNode = new StudentNode(StuName, StuNo, StuSex, StuAge, StuClass, StuHealth);
    if(first == NULL)
    {
        first = newNode;
    }
    else
    {
        StudentNode* iter = first;
        do
        {
            iter = iter->next;
        }
        while(iter->next != first);
        iter->next = newNode;
        newNode->next = first;
    }

}
bool StudentList::Insert(int i,const string& StuName, const long& StuNo, const string& StuSex,
                         const int& StuAge, const string& StuClass, const string& StuHealth)
{
    StudentNode* newNode = new StudentNode(StuName, StuNo, StuSex, StuAge, StuClass, StuHealth);
    if(i < 1)
    {
        cout << "Location error" << endl;
        return false;
    }
    if(i == 1)
    {
        first = newNode;
        newNode->next = first;
        return true;
    }
    else
    {
        StudentNode* pre = first;
        for(int j=1; j<i-1; j++)
        {
            pre = pre->next;
        }
        newNode->next = pre->next;
        pre->next = newNode;
        return true;
    }
}
bool StudentList::Remove(int i, string& StuName, long& StuNo, string& StuSex,
                         int& StuAge, string& StuClass, string& StuHealth)
{
    StudentNode* del;
    StudentNode* pre;
    if(IsEmpty())
    {
        cout << "Empty" << endl;
        return false;
    }
    if(i < 1)
    {
        cout << "Location error" << endl;
        return false;
    }
    if(i == 1)
    {
        del = first;
        first = del->next;
        StuName = del->Sname;
        StuNo = del->Sno;
        StuSex = del->Ssex;
        StuAge = del->Sage;
        StuClass = del->Sclass;
        StuHealth = del->Shealth;

        StudentNode* iter = LocateRear();
        iter->next = del->next;
        delete del;
        return true;
    }
    else
    {
        pre = first;
        if(pre->next == NULL)
        {
            cout << "Location error" << endl;
            return false;
        }
        pre = pre->next;
        for(int j = 1; j < i-2; j++)
        {
            if(pre->next == first)
            {
                cout << "Location error" << endl;
                return false;
            }
            pre = pre->next;
        }
        del = pre->next;
        pre->next = del->next;

        StuName = del->Sname;
        StuNo = del->Sno;
        StuSex = del->Ssex;
        StuAge = del->Sage;
        StuClass = del->Sclass;
        StuHealth = del->Shealth;

        delete del;
        return true;
    }
}

int main()
{
    StudentList Stu;
    int n, m;//n为人数，m为报数上限
    cin >> n >> m;
    for(int i = 0; i < n; i++)
    {
        string Sname;
        long Sno;
        string Ssex;
        int Sage;
        string Sclass;
        string Shealth;
        cin >> Sname >> Sno >> Ssex >> Sage >> Sclass >> Shealth;
        Stu.Insert(i+1, Sname, Sno, Ssex, Sage, Sclass, Shealth);
    }
    Stu.Output(n, m);

    return 0;
}

程序输出正常，但是不能正常结束。程序跳出Output函数开始执行return 0语句时会报错……不知道什么原因qwq求解。

[赵4老师]

百度搜相关关键字。

[大漠孤雁by]

#include<iostream> using namespace std; int main() { int i; //i用来记录数的那个数字 int n,m; int k,j; //k用来记录淘汰的人数 ,j用来表示第j个人 cout<<"请输入总人数 n和报数淘汰位 m:"; cin>>n>>m; int *Array=new int[n]; //用数组对n个人进行编号 for(i=0;i<n;i++) { Array[i]=i+1; } i=1; k=0; /*因为n个人围成一个圈，所以当j>n的时候，j要除n取余，例如（n+1）%n=1 之所以要++j，而不是j++是因为要先加1再判断*/ for(j=0;k<n-1;j=++j%n) { if(Array[j]!=0) //当j对应的人没有被淘汰时参与进来，淘汰的直接忽略 { if(i==m) //当j对应的人数到m的时候 { k++; //淘汰人数加1 Array[j]=0; //第K次淘汰的人(j+1)号对应数组的数据置为0 cout<<"第"<<k<<"次退出的是"<<j+1<<"号,\t "; i=1; //重新开始报数 } else { i++; //当j对应的人数没有数到m，则进行下一个 } } } for(i=0;i<n;i++) { if(Array[i]!=0) //通过上面的操作，所有淘汰的人员数组对应的值都为0，不为0的就是留下来的 { cout<<"留下来的是"<<i+1<<"号"<<endl; } } cout<<endl; system("pause") ; return 0; }

[x_xx_xxx_xxxx]

运行了一下你的程序，也遇到了崩溃，觉得是指针的问题。没有充裕时间细调试。没有确定下来

[赵4老师]

崩溃的时候在弹出的对话框按相应按钮进入调试，按Alt+7键查看Call Stack即“调用堆栈”里面从上到下列出的对应从里层到外层的函数调用历史。双击某一行可将光标定位到此次调用的源代码或汇编指令处，看不懂时双击下一行，直到能看懂为止。