Compilare: user.cpp: In function ‘void tr(int, int, int)’: user.cpp:15:5: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (x <= y) ^ user.cpp: In function ‘int main()’: user.cpp:72:6: warning: unused variable ‘sum’ [-Wunused-variable] int sum = 0, i, j; ^ user.cpp:72:15: warning: unused variable ‘i’ [-Wunused-variable] int sum = 0, i, j; ^ user.cpp:72:18: warning: unused variable ‘j’ [-Wunused-variable] int sum = 0, i, j; ^