Compilare: user.cpp: In function ‘void dijkstra()’: user.cpp:36:7: warning: unused variable ‘dist’ [-Wunused-variable] int dist = h.begin()->first; ^~~~ user.cpp:26:6: warning: unused variable ‘ma’ [-Wunused-variable] int ma = inf; ^~ user.cpp: In function ‘void read()’: user.cpp:57:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:61:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &length); ^ user.cpp: In function ‘int main()’: user.cpp:76:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.in", "r", stdin); ^ user.cpp:77:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.out", "w", stdout); ^