Compilare: user.cpp: In function ‘void DFS(int, int)’: user.cpp:77:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < knode[x].size(); ++ i) ^ user.cpp:84:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < G[x].size(); ++ i) ^ user.cpp:97:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < knode[x].size(); ++ j) ^ user.cpp: In function ‘void solve()’: user.cpp:134:12: warning: unused variable ‘x’ [-Wunused-variable] int i, x, y, k; ^ user.cpp:134:15: warning: unused variable ‘y’ [-Wunused-variable] int i, x, y, k; ^ user.cpp:134:18: warning: unused variable ‘k’ [-Wunused-variable] int i, x, y, k; ^ user.cpp: In function ‘void read()’: user.cpp:31:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:34:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp:40:31: 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:143:53: 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); ^ user.cpp: In function ‘void update(int)’: user.cpp:9:21: warning: ‘i’ is used uninitialized in this function [-Wuninitialized] #define zeros(x) (x & (-x)) ^ user.cpp:53:9: note: ‘i’ was declared here int i; ^ user.cpp: In function ‘int query(int)’: user.cpp:9:21: warning: ‘i’ is used uninitialized in this function [-Wuninitialized] #define zeros(x) (x & (-x)) ^ user.cpp:63:9: note: ‘i’ was declared here int i, res = 0; ^