Compilare: main.cpp: In function 'int main()': main.cpp:13:12: warning: statement has no effect [-Wunused-value] for (it;it<=im;it++) { ^ main.cpp:11:26: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d" ,&n); ^ main.cpp:12:48: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d%d%d" ,&it ,&jt ,&im ,&jm); ^