Compilare: user.cpp: In function ‘int main()’: user.cpp:22:62: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen("ture.in","r",stdin),freopen("ture.out","w",stdout); ^ user.cpp:22:62: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] user.cpp:23:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&n,&m,&k); ^ user.cpp:25:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(scanf("%d",&ii);ii;--ii) ^ user.cpp:26:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] { scanf("%d %d",&i,&j);--i,--j; ^