Question

我是C ++编码的新手，并且正在尝试自学课堂。我需要创建一个菜单驱动的程序，它将执行两个函数，一个用于查看字符串是否为回文，另一个用于查看找到两个数字的最大公分母。

我有一个main.cpp，一个GCD.cpp，一个palindrome.cpp，一个GCD.h和一个palindrome.h。当我在命令行上编译时，我收到以下错误：

/tmp/ccVf007n.o：在函数'main'中：main.cpp :(。test + 0x75）：对euclid（int，int）的未定义引用; collect2：错误：ld返回1退出状态。

我的代码块是： main.cpp中

#include <iostream>
#include "palindrome.h"
#include "GCD.h"
#include <string>
using namespace std;

void showChoices();
int x,y;

int main() {

int choice;
do
{
showChoices();
    cin >> choice;
    switch (choice)
    {
        case 1:
            cout << "Palindrome Program.";
            main();
            break;

        case 2:
            cout << "Greatest Common Denominator Program.";
            euclid(x,y);
            break;

        case 3:
            break;
    }

}while (choice !=3 );
}

void showChoices(){

cout << "Menu" << endl;
cout << "1. Palindrome Program" << endl;
cout << "2. Greatest Common Denominator Program" << endl;
cout << "3. Exit" << endl;
}

GCD.cpp

#include <iostream>
using namespace std;

int euclid (int*, int*);
int main() {
int a, b;
cout << "A program to find GCD of two given numbers.";
cout << "\n\nEnter your choice of a number: ";
cin >> a;
cout << "\nEnter your choice of another number: ";
cin >> b;

cout << "\n\nProcessing with Euclid method";
cout << "\nThe GCD of " << a << " and " << b << " is " << euclid(a, b);
return 0;
}

int euclid ( int *x, int *y) {
if ( x % y == 0 )
    reutrn y;
else return euclid ( y, x%y );

}

palindrome.cpp

#include<iostream>
using namespace std;

int main(){
char string1[20];
int i, length;
int flag = 0;

cout << "Enter a string: ";
cin >> string1;

length = strlen(string1);

for(i=0;i < length ;i++){
    if(string1[i] != string1[length-i-1]){
        flag = 1;
        break;
    }
}

if (flag) {
    cout << string1 << " is not a palindrome" << endl;
}
else {
    cout << string1 << " is a palindrome" << endl;
}
system("pause");
return 0;
}

GCD.h

#ifndef PROJ4_GCD_H
#define PROJ4_GCD_H

int euclid (int, int);

#endif //PROJ4_GCD_H

palindrome.h

#ifndef PROJ4_PALINDROME_H
#define PROJ4_PALINDROME_H

char string1[20];
int i, length;
int flag = 0;

#endif //PROJ4_PALINDROME_H

我感谢所有的投入和帮助。谢谢，

Answer 1

在标题中定义

int euclid (int, int);

但在您实施的.cpp文件中

int euclid (int*, int*);

因此，当您将其作为gcd(a, b)调用时，链接器将无法找到整数版本。摆脱指针。

PS：在您调用main()的交换机中，您需要拨打palindrome()：

switch (choice)
{
    case 1:
        cout << "Palindrome Program.";
        // main();
        palindrome();

菜单驱动程序中的未定义引用，带有两个函数头

1 个答案: