c++ - 段错误(核心已转储)C++ 错误

Question

我收到以下代码的“段错误(核心已转储)”错误:

#include <iostream>
#include <cstring>

template <class T>
T maxn(T* elements, int n);

template <> const char* maxn <const char*>(const char* elements[], int num);

int main(){
    using namespace std;

    //Using template
    int num[6] = {2, 3, 4, 5, 6, 22};
    double num2[4] = {16.6, 10.5, 2.3, 1.1};

    int larg = maxn(num, 6);
    double larg2 = maxn(num2, 4);
    cout << larg << endl << larg2 << endl;

    //Using specialization
    const char* pps[5] = {"Hello", "There", "I", "am", "me"};
    const char* largest = maxn(pps, 5);
    cout << largest << endl; 
    return 0;


}    

//return largest element in an array of T of n elements
template <class T>
T maxn(T* elements, int n){
    T largest = 0;
    for (int i=0; i<n; i++)
        largest = elements[i] > largest ? elements[i] : largest;
    return largest;
}    

//Returns address that points to the largest string
template <> const char* maxn <const char*>(const char* elements[], int num){
    int longest = 0;
    int i =0;
    for (i=0; i<num; i++)
        if (strlen(elements[i]) > strlen(elements[longest]))
            longest = i;
    return elements[i];
} 

我收到“警告:弃用的从字符串常量到‘char*’的转换”错误，但后来我将一些 char* 数组和函数参数更改为 const char*我摆脱了那个。现在代码编译，我得到以下输出:

22

16.6

段错误(核心已转储)

前两行是对的，但我不明白第三行发生了什么。请帮忙，谢谢。

Answer 1

你返回元素越界:

return elements[i];

应该是:

return elements[longest];

我可以建议在 for 循环中声明 i:

for (int i=0; i<num; i++)
//   ^^^^^^^

然后 return elements[i]; 行将抛出编译时错误。

当然，您应该优先考虑内置函数和容器 :)