Compilare: user.cpp: In function ‘int main()’: user.cpp:58:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inputFile.c_str(), "r", stdin); ^ user.cpp:59:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(outputFile.c_str(), "w", stdout); ^ user.cpp:62:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &N); ^ user.cpp:65:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &P[i].first, &P[i].second); ^ user.cpp:73:13: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] D[x] = 0; ^