Compilare: user.cpp: In function ‘int main()’: user.cpp:33:9: warning: unused variable ‘x’ [-Wunused-variable] int x, y, cost; ^ user.cpp:33:12: warning: unused variable ‘y’ [-Wunused-variable] int x, y, cost; ^ user.cpp:33:15: warning: unused variable ‘cost’ [-Wunused-variable] int x, y, cost; ^ user.cpp:38:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &N); ^ user.cpp:42:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &c[i][j]); ^