Finding the longest common suffix between two strings C++ - c++

Question

I'm fairly new to C++ and I can't seem to figure this out.
I get some weird output when running it. I am also trying to do this in the simplest way possible. How would I go about just printing the word in the suffix array and not all of the extra stuff. I have tried multiple ways to do this and they still show up.
#include <iostream>
#include <conio.h>
#include <string>
using namespace std;
int main(){
char word1[80];
char word2[80];
char suffix[80];
cout << "Enter the first word: ";
cin >> word1;
cout << "Enter the first word: ";
cin >> word1;
int len1 = strlen(word1);
int len2 = strlen(word2);
while(len1 > 0 && len2 > 0 && word1[len1] == word2[len2]) {
int k=0;
suffix[k]=word1[len1];
k++;
len1--;
len2--;
}
for(int i=strlen(suffix);i>=0; i--){
cout << suffix[i];
}
getch();
return 0;
}

Answer 1

Several things:
You should better use string instead of an array of char. That way,
you don't have to worry about memory.
The line int k=0; should be outside of the while.
Remember that arrays start at 0, so substract 1 from the length of
the words and iterate whilelen1 >= 0 && len2 >= 0
Using strings, you can use the method substr (reference
here).
Here is a modified version of your code:
#include <iostream>
#include <conio.h>
#include <string>
using namespace std;
int main() {
string word1,word2,suffix;
cout << "Enter the first word: ";
cin >> word1;
cout << "Enter the first word: ";
cin >> word2;
int len1 = word1.size()-1;
int len2 = word2.size()-1;
int k=0;
while(len1 >= 0 && len2 >= 0 && word1[len1] == word2[len2]) {
len1--;
len2--;
k++;
}
suffix=word1.substr(word1.size()-k,k);
cout << suffix;
getch();
return 0;
}

Answer 2

I always think the "simplest way possible" is to use someone else's work. Here
is one way to write your program that leverages the standard library:
#include <algorithm>
#include <string>
#include <iostream>
std::string suffix(const std::string& a, const std::string& b) {
size_t len = std::min(a.size(), b.size());
auto its = std::mismatch(a.rbegin(), a.rbegin()+len, b.rbegin());
return std::string(its.first.base(), a.end());
}
int main () {
std::cout << suffix("December", "May") << "\n";
std::cout << suffix("January", "February") << "\n";
std::cout << suffix("April", "April") << "\n";
}