Compilare: main.cpp: In function 'int main()': main.cpp:12:45: warning: unused variable 'lasty' [-Wunused-variable] int n,xs,ys,xf,yf,l,i,j,asize=0,rsize=0,lasty,firsty,nlast,nfirst; ^~~~~ main.cpp:12:51: warning: unused variable 'firsty' [-Wunused-variable] int n,xs,ys,xf,yf,l,i,j,asize=0,rsize=0,lasty,firsty,nlast,nfirst; ^~~~~~ main.cpp:12:58: warning: unused variable 'nlast' [-Wunused-variable] int n,xs,ys,xf,yf,l,i,j,asize=0,rsize=0,lasty,firsty,nlast,nfirst; ^~~~~ main.cpp:12:64: warning: unused variable 'nfirst' [-Wunused-variable] int n,xs,ys,xf,yf,l,i,j,asize=0,rsize=0,lasty,firsty,nlast,nfirst; ^~~~~~ main.cpp:10:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pipe.in","r",stdin); ^ main.cpp:11:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pipe.out","w",stdout); ^ main.cpp:14:45: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d\n",&n,&xs,&ys,&xf,&yf); ^ main.cpp:17:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c %d\n",&t,&l); ^