Compilare: user.cpp: In function ‘void read()’: user.cpp:13: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:14: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result user.cpp:15: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result user.cpp:16: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘void solve()’: user.cpp:38: warning: comparison between signed and unsigned integer expressions user.cpp:44: warning: comparison between signed and unsigned integer expressions user.cpp:44: warning: comparison between signed and unsigned integer expressions user.cpp:44: warning: comparison between signed and unsigned integer expressions user.cpp:58: warning: comparison between signed and unsigned integer expressions user.cpp:58: warning: comparison between signed and unsigned integer expressions user.cpp:69: warning: comparison between signed and unsigned integer expressions user.cpp:69: warning: comparison between signed and unsigned integer expressions user.cpp:80: warning: comparison between signed and unsigned integer expressions user.cpp:80: warning: comparison between signed and unsigned integer expressions user.cpp:91: warning: comparison between signed and unsigned integer expressions user.cpp:102: warning: comparison between signed and unsigned integer expressions user.cpp:113: warning: comparison between signed and unsigned integer expressions user.cpp:129: warning: comparison between signed and unsigned integer expressions user.cpp:143: warning: comparison between signed and unsigned integer expressions user.cpp:156: warning: comparison between signed and unsigned integer expressions user.cpp:169: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:198: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:199: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result In file included from /usr/include/stdio.h:910, from /usr/include/c++/4.4/cstdio:45, from user.cpp:1: In function ‘char* fgets(char*, int, FILE*)’, inlined from ‘void read()’ at user.cpp:14: /usr/include/bits/stdio2.h:253: warning: call to ‘__fgets_chk_warn’ declared with attribute warning: fgets called with bigger size than length of destination buffer In function ‘char* fgets(char*, int, FILE*)’, inlined from ‘void read()’ at user.cpp:15: /usr/include/bits/stdio2.h:253: warning: call to ‘__fgets_chk_warn’ declared with attribute warning: fgets called with bigger size than length of destination buffer In function ‘char* fgets(char*, int, FILE*)’, inlined from ‘void read()’ at user.cpp:16: /usr/include/bits/stdio2.h:253: warning: call to ‘__fgets_chk_warn’ declared with attribute warning: fgets called with bigger size than length of destination buffer user.cpp: In function ‘void prepare()’: user.cpp:21: warning: ‘type’ may be used uninitialized in this function