Compilare: user.cpp: In function ‘void add_Hash(long long int, int, int)’: user.cpp:17:15: warning: statement has no effect [-Wunused-value] for(it; it != Hash[x % MOD].end() ; ++it) ^ user.cpp: In function ‘bool find_Hash(long long int)’: user.cpp:28:15: warning: statement has no effect [-Wunused-value] for(it; it != Hash[x % MOD].end() ; ++it) ^ user.cpp: In function ‘void solve()’: user.cpp:86:19: warning: statement has no effect [-Wunused-value] for(it; it != Hash[Hash2 % MOD].end() ; ++it){ ^ user.cpp: In function ‘int main()’: user.cpp:125:9: warning: unused variable ‘x’ [-Wunused-variable] int x = k, pas = 0; ^ user.cpp:114:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colectie.in", "r", stdin); ^ user.cpp:115:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colectie.out", "w", stdout); ^ user.cpp:116:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:119:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^