Compilare: user.cpp: In function ‘int main()’: user.cpp:45:7: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (ok(a + di[j]) && ok(b + dj[j]) && p.find(make_pair(a + di[j], b + dj[j])) != p.end()) ^ user.cpp:40:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi, "%d %d", &n, &k); ^ user.cpp:43:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi, "%d %d", &a, &b); ^