Search my name in statement ! in c program using string functions

Question

I need to know whats wrong with this code.

#include<stdio.h>
#include<string.h>

int main() {
    char a[50], b[100], c[5000];
    char *ret;
    //enter first name
    gets(a);
    //enter secend name 
    gets(b);
    //enter statement
    gets(c);

    strcat(a,b);

    if(strstr(c,a) != NULL) {
        printf("found your full name");
    } else {
        printf("not found your full name");
    }
    return 0;
}

It does not work when, I use the following lines:

mohamed
ramadan
abdelrhmanamirelbatanonywoofymohamedramadanahmedalyomarelazazyahmedkamelahmedsa‌​lemessamelnaggarkhaledhelmy

It should find something, but the programm tells me, that it hasn't.

Answer 1

• Point 1

  As per the man page of strcat()

  char *strcat(char *dest, const char *src);

  If dest is not large enough, program behavior is unpredictable

  In your case,

  strcat(a,b);
  

  a maybe not having enough memory to hold the concatenated string. Possible UB. Change the logic.

• Point 2

  gets() suffers from buffer overflow issue. Use fgets() instead.