Compilare: user.cpp: In function ‘long long int getMax2DSubArray(long long int (*)[2001], int, int)’: user.cpp:55:13: warning: variable ‘start2’ set but not used [-Wunused-but-set-variable] int start2=0,start3=0,start4=0; ^ user.cpp:55:31: warning: variable ‘start4’ set but not used [-Wunused-but-set-variable] int start2=0,start3=0,start4=0; ^ user.cpp:56:13: warning: variable ‘end2’ set but not used [-Wunused-but-set-variable] int end2=0,end3=0,end4=0; ^ user.cpp:56:27: warning: variable ‘end4’ set but not used [-Wunused-but-set-variable] int end2=0,end3=0,end4=0; ^ user.cpp: In function ‘int main()’: user.cpp:166:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &n, &m); ^ user.cpp:168:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%lld", &a[i]); ^ user.cpp:171:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%lld", &b[j]); ^