Compilare: main.cpp: In function 'void dfs_down(int, int)': main.cpp:15:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[nod].size() ; i++){ ~~^~~~~~~~~~~~~~~ main.cpp:31:20: 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(int, int)': main.cpp:53:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[nod].size() ; i++){ ~~^~~~~~~~~~~~~~~ main.cpp:71:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[tt].size() ; i++){ ~~^~~~~~~~~~~~~~ main.cpp:91:20: 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:110:25: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&n); ^ main.cpp:112:44: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d%d%d",&x,&y,&a,&b); ^ main.cpp: In function 'void dfs_up(int, int)': main.cpp:80:72: warning: 'c_in' may be used uninitialized in this function [-Wmaybe-uninitialized] + down_in[tt] - max(0LL , down_in[nod] + c_in) + c_in + up_in[tt]); ~~~~~~~~~~~~~^~~~~~