Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:43:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < g[x].size(); i++) ~~^~~~~~~~~~~~~ user.cpp:47:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(s = i = 0; i < g[x].size(); i++) ~~^~~~~~~~~~~~~ user.cpp:57:12: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] k = i+j+1>>1; ~~~^~ user.cpp: In function ‘int solve()’: user.cpp:72:13: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] mid = le+ri>>1; ~~^~~