Compilare: user.cpp: In function ‘int main()’: user.cpp:70:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d", &x, &n); ^ user.cpp:71:76: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i = 1; i <= n; i++) fscanf(fi,"%d", &o[i]), from[o[i]] = {i, 0}; ^ user.cpp:72:76: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i = 1; i <= n; i++) fscanf(fi,"%d", &v[i]), from[v[i]] = {i, 1}; ^