Compilare: user.cpp: In function ‘int main()’: user.cpp:47:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i!=j && strlen(v[j]+1)>=l) ^ user.cpp:13:22: warning: unused variable ‘k’ [-Wunused-variable] int n,p,l,maxx=0,k,l1,r=0,a; ^ user.cpp:11:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("interesant.in","r",stdin); ^ user.cpp:12:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("interesant.out","w",stdout); ^ user.cpp:14:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n",&p,&n); ^ user.cpp:19:24: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sir+1); ^ user.cpp:42:25: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(v[i]+1); ^ In file included from /usr/include/stdio.h:934:0, from /usr/include/c++/4.8/cstdio:42, from user.cpp:1: In function ‘char* gets(char*)’, inlined from ‘int main()’ at user.cpp:42:25: /usr/include/i386-linux-gnu/bits/stdio2.h:230:28: warning: call to ‘__gets_warn’ declared with attribute warning: please use fgets or getline instead, gets can't specify buffer size [enabled by default] return __gets_warn (__str); ^ /tmp/ccNrGJMi.o: In function `main': user.cpp:(.text.startup+0x90): warning: the `gets' function is dangerous and should not be used. user.cpp:(.text.startup+0x2d3): warning: the `gets' function is dangerous and should not be used.