Compilare: user.cpp: In function ‘void task(int)’: user.cpp:45:14: warning: variable ‘ok’ set but not used [-Wunused-but-set-variable] bool ok = 0; ^ user.cpp: In function ‘int main()’: user.cpp:83:9: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(s + 1); ^ In file included from /usr/include/c++/5/cstdio:42:0, from /usr/include/x86_64-linux-gnu/c++/5/32/bits/stdc++.h:46, from user.cpp:1: /usr/include/stdio.h:638:14: note: declared here extern char *gets (char *__s) __wur __attribute_deprecated__; ^ user.cpp:83:9: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(s + 1); ^ In file included from /usr/include/c++/5/cstdio:42:0, from /usr/include/x86_64-linux-gnu/c++/5/32/bits/stdc++.h:46, from user.cpp:1: /usr/include/stdio.h:638:14: note: declared here extern char *gets (char *__s) __wur __attribute_deprecated__; ^ user.cpp:83:19: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(s + 1); ^ In file included from /usr/include/c++/5/cstdio:42:0, from /usr/include/x86_64-linux-gnu/c++/5/32/bits/stdc++.h:46, from user.cpp:1: /usr/include/stdio.h:638:14: note: declared here extern char *gets (char *__s) __wur __attribute_deprecated__; ^ user.cpp:111:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 2; j <= S[i].size(); ++ j) ^ user.cpp:79:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d\n", &T, &n, &m); ^ user.cpp:83:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); ^ /tmp/cc7tv0JE.o: In function `main': user.cpp:(.text.startup+0x85): warning: the `gets' function is dangerous and should not be used.