Compilare: main.cpp: In function 'void dfs_down(long long int, long long int)': main.cpp:12:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[nod].size() ; i++){ ~~^~~~~~~~~~~~~~~ main.cpp: In function 'void dfs_up(long long int, long long int)': main.cpp:37:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[nod].size() ; i++){ ~~^~~~~~~~~~~~~~~ main.cpp:55:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[tt].size() ; i++){ ~~^~~~~~~~~~~~~~ main.cpp:75:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[nod].size() ; i++){ ~~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:94:27: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%lld",&n); ^ main.cpp:96:52: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%lld%lld%lld%lld",&x,&y,&a,&b); ^ main.cpp: In function 'void dfs_up(long long int, long long int)': main.cpp:64:80: warning: 'c_in' may be used uninitialized in this function [-Wmaybe-uninitialized] up_out[nod] = max(up_out[nod] , max(0LL , max(0LL , down_out[vecin] + c1) - max(0LL , down_in[vecin] + c2)) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + down_in[tt] - max(0LL , down_in[nod] + c_in) + c_in + up_in[tt]); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~