Compilare: user.cpp: In function ‘int main()’: user.cpp:12:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i<=strlen(s1+1)&&ind<=strlen(s2+1); ++i) { ^ user.cpp:12:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i<=strlen(s1+1)&&ind<=strlen(s2+1); ++i) { ^ user.cpp:7:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sr.in","r",stdin); ^ user.cpp:8:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sr.out","w",stdout); ^ user.cpp:9:15: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s1+1); ^ user.cpp:10:15: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s2+1); ^ /tmp/ccMExdvT.o: In function `main': user.cpp:(.text.startup+0x60): warning: the `gets' function is dangerous and should not be used.