Compilare: user.cpp: In function ‘void solve()’: user.cpp:51:81: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(nstp[it->first] > nstp[x] + 1 || nstp[it->first] == nstp[x] + 1 && cost[it->first] > cost[x] + it->second){ ^ user.cpp: In function ‘void read()’: user.cpp:22:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&n ); ^ user.cpp:23:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&k ); ^ user.cpp:25:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ",&x ,&y ); ^ user.cpp:28:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&k ); ^ user.cpp:30:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ",&x ,&y ); ^ user.cpp: In function ‘int main()’: user.cpp:63:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scara3.in","r",stdin); ^ user.cpp:64:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("scara3.out","w",stdout); ^