Compilare: main.cpp: In function 'void down_dfs(int)': main.cpp:50:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<graph[node].size(); ++i)if(graph[node][i].node!=dad[node]){ ~^~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void up_dfs(int, int)': main.cpp:60:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<graph[node].size(); ++i) graph[node][i].left=max(graph[node][i].left, graph[node][i-1].left); ~^~~~~~~~~~~~~~~~~~~ main.cpp:66:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(nr==graph[up].size()-1) sol[node]=max(sol[node], graph[up][nr-1].left+graph[up][nr].val); ~~^~~~~~~~~~~~~~~~~~~~ main.cpp:68:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<graph[node].size(); ++i) if(graph[node][i].node==up) ~^~~~~~~~~~~~~~~~~~~ main.cpp:71:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<graph[node].size(); ++i) if(graph[node][i].node!=dad[node])up_dfs(graph[node][i].node, i); ~^~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:17:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("razboi.in", "r", stdin); ^ main.cpp:18:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("razboi.out", "w", stdout); ^ main.cpp:19:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ main.cpp:22:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:26:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &d); ^