Compilare: user.cpp: In function ‘int first_dfs(int, int)’: user.cpp:33:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(check(l0,c0)==true) ^ user.cpp:41:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int second_dfs(int, int)’: user.cpp:54:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:56:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("volum.in","r",stdin); ^ user.cpp:57:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("volum.out","w",stdout); ^ user.cpp:59:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:62:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&h[i][j]); ^