Compilare: user.cpp: In function ‘void solve_test()’: user.cpp:15:5: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(s + 1); ^~~~ In file included from /usr/include/c++/6/cstdio:42:0, from /usr/include/x86_64-linux-gnu/c++/6/32/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:15:15: warning: ‘char* gets(char*)’ is deprecated [-Wdeprecated-declarations] gets(s + 1); ^ In file included from /usr/include/c++/6/cstdio:42:0, from /usr/include/x86_64-linux-gnu/c++/6/32/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:14:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &N); ^ user.cpp:15:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); ^ user.cpp: In function ‘int main()’: user.cpp:43:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("eqprob.in", "r", stdin); ^ user.cpp:44:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("eqprob.out", "w", stdout); ^ user.cpp:47:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); ^ /tmp/ccOQ56eG.o: In function `solve_test()': user.cpp:(.text+0x2a): warning: the `gets' function is dangerous and should not be used.