Compilare: user.cpp: In function ‘int main()’: user.cpp:17:13: warning: unused variable ‘left’ [-Wunused-variable] int n, m, left, right, dif = 0, difc; ^ user.cpp:17:19: warning: unused variable ‘right’ [-Wunused-variable] int n, m, left, right, dif = 0, difc; ^ user.cpp:20:30: 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:23:37: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &matr[l][c]); ^