Compilare: user.cpp: In function ‘void read()’: user.cpp:17:9: warning: unused variable ‘x’ [-Wunused-variable] int x, y, k; ^ user.cpp: In function ‘void solve()’: user.cpp:114:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < pos[i].size()-1; j++) ^ user.cpp: In function ‘void read()’: user.cpp:18:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:20:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &k); ^ user.cpp:22:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &y); ^ user.cpp: In function ‘int main()’: user.cpp:122:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sushi2.in", "r", stdin); ^ user.cpp:123:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sushi2.out", "w", stdout); ^ user.cpp:138:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &t); ^