Compilare: user.cpp: In function ‘int main()’: user.cpp:25:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v[x1][j]==a[i]) ^ user.cpp:57:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v[x1][k]==a[j]) ^ user.cpp:78:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v[x1][k]==a[j]) ^ user.cpp:98:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v[x1][k]==a[j]) ^ user.cpp:123:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v2[x1][j]==a[i]) ^ user.cpp:155:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v2[x1][k]==a[j]) ^ user.cpp:11:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("secv5.in","r",stdin); ^ user.cpp:12:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("secv5.out","w",stdout); ^ user.cpp:13:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d", &n, &l, &r); ^ user.cpp:18:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%ud", &a[i]); ^