Compilare: user.cpp: In function ‘int main()’: user.cpp:67:69: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sortnet.in", "r", stdin),freopen("sortnet.out","w",stdout); ^ user.cpp:67:69: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] user.cpp:68:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &nwires, &depth); ^ user.cpp:71:57: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf(" <%d ,%d >", &gates[i][j].lo, &gates[i][j].hi); ^