Compilare: user.cpp: In function ‘int main()’: user.cpp:46:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j + 1 < r[i].size(); ++j) ^ user.cpp:30:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen("restrictii.in", "r", stdin); ^ user.cpp:31:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("restrictii.out", "w", stdout); ^ user.cpp:33:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &m, &val); ^ user.cpp:37:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &must); ^