Compilare: main.cpp: In function 'int main()': main.cpp:19:23: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] s[strlen(s2+1)+2]=NULL; ^~~~ main.cpp:36:23: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] s[strlen(s2+1)+2]=NULL; ^~~~ main.cpp:54:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<=strlen(s2+1)/2; i++){ ~^~~~~~~~~~~~~~~~ main.cpp:12:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] { freopen("aparitii2.in", "r",stdin); ^ main.cpp:13:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("aparitii2.out", "w",stdout); ^ main.cpp:15:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", s1+1); ^ main.cpp:16:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", s2+1); ^