Compilare: user.cpp: In function ‘void insert_hash(int, int, int)’: user.cpp:37:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < V[x][y].size(); ++ i) ^ user.cpp: In function ‘int in_hash(int, int)’: user.cpp:48:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < V[x][y].size(); ++ i) ^ user.cpp: In function ‘void solve()’: user.cpp:83:27: warning: format ‘%s’ expects argument of type ‘char*’, but argument 2 has type ‘char (*)[32]’ [-Wformat=] scanf("%s ", &b[i]); ^ user.cpp: In function ‘void read()’: user.cpp:55:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sabin.in", "r", stdin); ^ user.cpp:56:50: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d %d\n", &n, &k, &m, &p, &q); ^ user.cpp: In function ‘void solve()’: user.cpp:68:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s ", a[i][j]); ^ user.cpp:69:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("\n"); ^ user.cpp:83:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s ", &b[i]); ^ user.cpp: In function ‘void write()’: user.cpp:88:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sabin.out", "w", stdout); ^ user.cpp:91:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &x); ^ user.cpp:95:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &pos[i]); ^