Compilare: user.cpp: In function ‘void Dijkstra()’: user.cpp:140:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < V[x].size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:107:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retea.in", "r", stdin); ^ user.cpp:108:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &m, &k); ^ user.cpp:111:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %lf", &x, &y, &cost); ^ user.cpp: In function ‘void write()’: user.cpp:162:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retea.out", "w", stdout); ^