Compilare: user.cpp: In function ‘int main()’: user.cpp:35:87: warning: operation on ‘vf’ may be undefined [-Wsequence-point] if(vf > 1 && stiva[vf].x == stiva[vf-1].y+1) stiva[vf-1].y = stiva[vf--].x; ^ user.cpp:20:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&K); ^ user.cpp:24:55: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i = 1; i <= K; ++i) fscanf(fin,"%d",&v[i]); ^