String Concatenation Programe in C/C++

[OraMaster]

Hi All,

I just want to know the different approch for this program to build from experts. Program is like we provide 2 strings as input and output string should contain both input strings as substrings.
for e.g
1. Input=> str1: abcd str2: bcde Output: abcde
2. Input=> str1: bcdf str2: dfyn Output: bcdfyn
3. Input=> str1: ytmsqp str2: msqps Output: ytmsqps

Also pls provide me some tough combinations of input and output.
I did this program so pls don't consider this is my HW :)

[Banfa]

I would think the algorithm would be something like

LOOP n = 1 to length(String1)
    IF character n of String1 == character 1 of String2
        IF last characters of String1 == first characters of String2
            Terminate String1 at n
            Concatinate String2 onto String1
            Force End of Loop
        ENDIF
    ENDIF
ENDLOOP
 
IF LOOP ended naturally rather than being forced
    Concatinate String2 onto String1
ENDIF
 

Try the following combinations

abcde and fghij producing abcdefghij
abcde and cdfgh producing abcdecdfgh
abcdecd and cdfgh producing abcdecdfgh

[OraMaster]

@Banfa
Thanks! Sounds Good.

[JosAH]

If you want your two string S1 and S2 to be S1 == Xp and S2 == pY and the output to be XY where |p| (the length of substring p) to be maximal have a look at the 'failure function' used in the Boyer-Moore algoritm as well as the Knuth-Morris-Pratt algorithm. You can find substring p in linear time, i.e. O(|p|) instead of quadratic time as shown by Banfas algorithm. (Google is your friend).

kind regards,

Jos