Compilare: user.cpp: In function ‘bigInt operator<<(bigInt&, int)’: user.cpp:22:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size(); ++i) ^ user.cpp: In function ‘bigInt operator+(bigInt, bigInt)’: user.cpp:33:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); ++i) ^ user.cpp:35:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] a[i] += (i < b.size() ? b[i] : 0) + t; ^ user.cpp: In function ‘bigInt operator*(int, bigInt)’: user.cpp:54:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); ++i) ^ user.cpp: In function ‘bool comp(bigInt&, bigInt)’: user.cpp:75:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] int d1 = (i < a.size() ? a[i] : 0); ^ user.cpp:76:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] int d2 = (i < b.size() ? b[i] : 0); ^ user.cpp: In function ‘int main()’: user.cpp:111:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sqrt.in", "r", stdin); ^ user.cpp:112:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sqrt.out", "w", stdout); ^