Compilare: user.cpp: In function ‘int main()’: user.cpp:67:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < pr.size(); ++ i) ^ user.cpp:79:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); ++ i) ^ user.cpp:81:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < sol[i].size(); ++ j) ^ user.cpp:33:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("piese3.in", "r", stdin); ^ user.cpp:34:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("piese3.out", "w", stdout); ^ user.cpp:38:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i", &t); ^ user.cpp:43:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i %i", &n, &c); ^ user.cpp:49:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i", &val); ^