Compilare: user.cpp: In function ‘void rezolva()’: user.cpp:129:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=1; j<val[i].size(); j++) ^ user.cpp:136:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<val[i].size(); j++) ^ user.cpp:120:19: warning: unused variable ‘nr’ [-Wunused-variable] int i, j, k, nr=0; ^ user.cpp: In function ‘void solve()’: user.cpp:156:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("control.in", "r", stdin); ^ user.cpp:157:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("control.out", "w", stdout); ^ user.cpp:158:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:162:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(lin); ^ /tmp/cczxbytT.o: In function `solve()': user.cpp:(.text+0xa9d): warning: the `gets' function is dangerous and should not be used.