Compilare: user.cpp: In function ‘void bellman_ford()’: user.cpp:39:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i<arcs[curr_node].size(); ++i) ~^~~~~~~~~~~~~~~~~~~~~~~ user.cpp: In function ‘bool dijkstra()’: user.cpp:87:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<arcs[curr_node].size(); ++i) ~^~~~~~~~~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:141:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fmcm.in", "r", stdin); ^ user.cpp:142:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fmcm.out", "w", stdout); ^ user.cpp:145:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &source, &dest); ^ user.cpp:149:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:153:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &caps[x][y], &costs[x][y]); ^