Compilare: user.cpp: In function ‘std::vector<int> multiply(const std::vector<int>&, const std::vector<int>&)’: user.cpp:87:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < va.size(); ++i) nc.push_back(va[i] * vb[i]); ~~^~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:129:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < c.size(); ++i) ~~^~~~~~~~~~ user.cpp:101:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bacterii2.in", "r", stdin); ^ user.cpp:102:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bacterii2.out", "w", stdout); ^ user.cpp:115:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(scanf("%d", &t); t; --t) { ^ user.cpp:121:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:122:56: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i = 1; i <= n; ++i) scanf("%d", &x), a[x]++; ^ user.cpp:124:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); ^ user.cpp:125:56: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i = 1; i <= m; ++i) scanf("%d", &x), b[x]++; ^