Compilare: main.cpp: In function 'int main()': main.cpp:21:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d",&n,&m); ^ main.cpp:23:30: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d",&a,&b); ^ main.cpp:28:9: warning: iteration 50000 invokes undefined behavior [-Waggressive-loop-optimizations] d[i]=-1; ~~~~^~~ main.cpp:27:12: note: within this loop for(i=1;i<=50001;i++) ~^~~~~~~