Compilare: main.cpp: In function 'void solve()': main.cpp:31:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ocupiedLines.size() < k) { ~~~~~~~~~~~~~~~~~~~~^~~ main.cpp:49:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ocupiedColumns.size() < k) ~~~~~~~~~~~~~~~~~~~~~~^~~ main.cpp: In function 'int main()': main.cpp:101:53: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("nave_interdimensionale.in", "r", stdin); ^ main.cpp:102:55: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("nave_interdimensionale.out", "w", stdout); ^ main.cpp: In function 'void solve()': main.cpp:65:23: warning: 'elmini' may be used uninitialized in this function [-Wmaybe-uninitialized] columns[elmini] --; ~~~~~~~~~~~~~~^ main.cpp:46:21: warning: 'elmini' may be used uninitialized in this function [-Wmaybe-uninitialized] lines[elmini] --; ~~~~~~~~~~~~^