Compilare: user.cpp: In function ‘int main()’: user.cpp:34:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < v.size(); j++) { ^ user.cpp:37:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k = 0; k < v.size(); k++) { ^ user.cpp:39:45: warning: suggest parentheses around comparison in operand of ‘^’ [-Wparentheses] if(i ^ (1 << k) != 0 && ^ user.cpp:47:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k = 1; k < prrev.size(); k++) { ^ user.cpp:60:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v.size(); i++) { ^ user.cpp:13:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bibel.in", "r", stdin); ^ user.cpp:14:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bibel.out", "w", stdout); ^ user.cpp:21:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a); ^ user.cpp:26:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ In file included from /usr/include/string.h:642:0, from /usr/include/c++/4.8/cstring:42, from user.cpp:3: In function ‘void* memset(void*, int, size_t)’, inlined from ‘int main()’ at user.cpp:32:32: /usr/include/i386-linux-gnu/bits/string3.h:82:32: warning: call to ‘__warn_memset_zero_len’ declared with attribute warning: memset used with constant zero length parameter; this could be due to transposed parameters [enabled by default] __warn_memset_zero_len (); ^ /tmp/ccaeSV9g.o: In function `main': user.cpp:(.text.startup+0x112): warning: memset used with constant zero length parameter; this could be due to transposed parameters