Question

这是我的代码：

#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

string checkpalindrome(string sentence){
    sentence.erase(std::remove(sentence.begin(), sentence.end(), ' '), sentence.end());

    int unsigned i = 0;
    for (i = 0; i < sentence.length(); i++){
        sentence[i] = tolower(sentence[i]);
    }

    if (sentence == string(sentence.rbegin(), sentence.rend())){
        cout << sentence << " is a palindrome." << endl;
    }
    if(sentence != string(sentence.rbegin(), sentence.rend())){
        cout << sentence << " isn't a palindrome." << endl;
    }
   return 0;
}

int main(){
    int x = 1;
    string originalsentence;
    while (x == 1){
        int input;
        string sentence;
        cout << "Press 1 to reverse a string, 2 to check a palindrome, and anything else to quit: ";
        cin >> input;

        if(input == 1){
            cout << "Enter a sentence to reverse: ";
            cin.ignore(256, '\n');
            getline(cin,originalsentence);
            sentence = originalsentence;
            cout << string(sentence.rbegin(), sentence.rend()) << endl;
        }

        if(input == 2) {
            cout << "Enter a sentence to check: ";
            cin.ignore(256, '\n');
            getline(cin,originalsentence);
            sentence = originalsentence;
            checkpalindrome(sentence);
        }

        cout << "Hit 1 if you want to continue, anything else to quit: ";
        cin >> x;
    }
}

程序完成并完成它应该做的所有事情，除非我做选项2检查回文，最后，它总是核心转储。我试过包括cin.ignore's，但他们没有帮助。有什么想法吗？

编辑1：所以我改变了g ++抛出的三个警告。他们是palindrome.cpp:19: warning: comparison between signed and unsigned integer expressions palindrome.cpp:29: warning: no return statement in function returning non-void palindrome.cpp:35: warning: unused variable âaâ

我将int i更改为无符号，在28处返回0，并删除了a。现在当我编译它时没有给出任何错误，但是当我运行它时，它仍然会在完成回文检查时崩溃，并出现此错误。 terminate called after throwing an instance of 'std::logic_error' what(): basic_string::_S_construct NULL not valid Abort (core dumped) 还有更多想法吗？

Answer 1

复制自问题：

固定！我需要做的只是return sentence，它现在没有错误

分段故障 - 核心转储

1 个答案: