Compilare: main.cpp: In function 'std::vector<int> baga(std::vector<int>, std::vector<int>)': main.cpp:14:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <= a.size(); ++i) ~~^~~~~~~~~~~ main.cpp:15:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j <= b.size(); ++j) { ~~^~~~~~~~~~~ main.cpp:37:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <= a.size(); ++i) ~~^~~~~~~~~~~ main.cpp:38:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j <= b.size(); ++j) ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:73:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < sol.size(); ++i) ~~^~~~~~~~~~~~ main.cpp:56:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("purification.in", "r", stdin); ^ main.cpp:57:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("purification.out", "w", stdout); ^ main.cpp:60:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:62:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ main.cpp:65:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^