Compilare: user.cpp: In function ‘int query(int)’: user.cpp:59:9: warning: unused variable ‘i’ [-Wunused-variable] int i, res = 0; ^ user.cpp: In function ‘void DFS(int, int)’: user.cpp:71:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < knode[x].size(); ++ i) ^ user.cpp:81:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < G[x].size(); ++ i) ^ user.cpp:68:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp: In function ‘void solve()’: user.cpp:130:12: warning: unused variable ‘x’ [-Wunused-variable] int i, x, y, k; ^ user.cpp:130:15: warning: unused variable ‘y’ [-Wunused-variable] int i, x, y, k; ^ user.cpp:130:18: warning: unused variable ‘k’ [-Wunused-variable] int i, x, y, k; ^ user.cpp: In function ‘void read()’: user.cpp:29:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:32:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp:38:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &speed[i]); ^ user.cpp: In function ‘void solve()’: user.cpp:139:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &Q[i].u, &Q[i].v, &Q[i].k); ^