Compilare: user.cpp: In function ‘int main()’: user.cpp:62:9: warning: unused variable ‘r’ [-Wunused-variable] int r=1, s, k; ^ user.cpp:62:14: warning: unused variable ‘s’ [-Wunused-variable] int r=1, s, k; ^ user.cpp:62:17: warning: unused variable ‘k’ [-Wunused-variable] int r=1, s, k; ^ user.cpp:49:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&m,&n); ^ user.cpp:55:38: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&a[i][j]); ^