Compilare: main.cpp: In function 'int main()': main.cpp:44:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (x1 < aer[a].size () && aer[a][x1].x <= l + 1) ~~~^~~~~~~~~~~~~~~~ main.cpp:46:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (x2 < aer[b].size () && aer[b][x2].x <= l + 1) ~~~^~~~~~~~~~~~~~~~ main.cpp:21:44: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("carpetbomber.in", "r", stdin); ^ main.cpp:22:46: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("carpetbomber.out", "w", stdout); ^