Compilare: user.cpp: In function ‘int main()’: user.cpp:25:21: warning: unused variable ‘con’ [-Wunused-variable] int n, m, x, y, con = 0; ^ user.cpp:26:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d", &n, &m); ^ user.cpp:29:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d", &x, &y); ^