Compilare: user.cpp: In function ‘int main()’: user.cpp:82:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < costuri [i].size (); ++ j) ^ user.cpp:63:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("tunel.in", "r", stdin); ^ user.cpp:64:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("tunel.out", "w", stdout); ^ user.cpp:66:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &n, &m); ^ user.cpp:68:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d", &x, &y, &c); ^