Compilare: main.cpp: In function 'void change(std::vector<int>&, int&)': main.cpp:12:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < prm.size(); ++i) { ~~^~~~~~~~~~~~ main.cpp:14:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i; j + 1 < prm.size(); ++j) ~~~~~~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:30:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cabane.in", "r", stdin); ^ main.cpp:31:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cabane.out", "w", stdout); ^