在调试器模式下工作.在可执行模式下崩溃

Question

该代码是在VS社区2013中编写的.该程序在调试器模式下运行良好.但执行时坠毁了.请让我知道可能是什么问题.样本测试案例:10 aaa bbb ccc aaa

该程序在第3个输入行崩溃,有时在第4个输入行.

#include<iostream>
#include<string.h>
#include<string>
using namespace std;
class registeration
{
public:
    char* name;
    int count;
    registeration *next;

    registeration()
    {
        name = new char(20);
        count = 0;
        next = NULL;
    }
};
int main()
{
    int n;
    cin >> n;
    char* str = new char(n);
    registeration *regStart = new registeration();

    while (n--)
    {
        cin >> str;
        if (regStart->next == NULL)
        {
            registeration *reg = new registeration();
            regStart->next = reg;
            reg->count++;
            //strcpy(reg->name, str);
            strcpy_s(reg->name, 20, str);
        }
        else
        {
            registeration *reg = new registeration();
            reg = regStart->next;
            while (reg->next != NULL && strcmp(str, reg->name))
            {
                //registeration *reg1 = new registeration();
                reg = reg->next;
            }
            if (!strcmp(str, reg->name))
                reg->count++;
            else
            {
                registeration *reg1 = new registeration();
                strcpy_s(reg1->name, 20, str);
                reg1->count++;
                reg->next = reg1;

            }
        }
    }
    registeration *reg = new registeration();
    reg = regStart->next;
    while (reg != NULL)
    {
        if (reg->count > 1)
            cout << reg->name << endl;
        reg = reg->next;
    }
    return 0;
}

Answer 1

这些行中有一个明显的错误:

name = new char(20);
char* str = new char(n);

它们分配一个初始化为给定值的单个字符.相反,您打算分配一个字符数组,您可以按如下方式进行操作:

name = new char[20];
char* str = new char[n];

(用括号代替括号.)

最好使用标准C++实用程序为您管理内存,例如std::string字符串和/ std::vector或std::list容器.

编辑:此代码与您的代码完全相同,更好:

#include <iostream>
#include <string>
#include <map>
using namespace std;

int main()
{
    int n;
    cin >> n;

    map<string, int> m;
    for(int i = 0; i < n; ++i)
    {
        string s;
        cin >> s;
        m[s]++;
    }

    for(const auto &pr : m)
        if(pr.second > 1)
            cout << pr.first << '\n';
}