Compilare: user.cpp: In function ‘void bellman_ford()’: user.cpp:40:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i<arcs[curr_node].size(); ++i) ~^~~~~~~~~~~~~~~~~~~~~~~ user.cpp: In function ‘bool dijkstra()’: user.cpp:83:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<arcs[curr_node].size(); ++i) ~^~~~~~~~~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:129:35: 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:130:37: 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:133:46: 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:137:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:141:49: 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]); ^