Compilare: user.cpp: In function ‘bool bellmanford()’: user.cpp:24:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<v[i].size(); ++j) ^ user.cpp:31:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<v[i].size(); ++j) ^ user.cpp: In function ‘int main()’: user.cpp:41:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bellmanford.in", "r", stdin); ^ user.cpp:42:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bellmanford.out", "w", stdout); ^ user.cpp:46:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:50:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &aux.x, &aux.c); ^