Compilare: user.cpp: In function ‘int main()’: user.cpp:77:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &n); ^ user.cpp:78:57: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=0; i<n; i++) fscanf(fin, "%d%d", &x[i], &y[i]); ^ user.cpp:79:16: warning: array subscript is below array bounds [-Warray-bounds] a=1LL*x[n-1]*y[0]-1LL*x[0]*y[n-1]; ^ user.cpp:79:37: warning: array subscript is below array bounds [-Warray-bounds] a=1LL*x[n-1]*y[0]-1LL*x[0]*y[n-1]; ^ user.cpp:69:5: warning: ‘t’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(i=0; i<k; i++) p[i]=aux[i], ok[i]=0; ^ user.cpp:31:15: note: ‘t’ was declared here int s, i, t; ^