Compilare: user.cpp: In function ‘void palindrom()’: user.cpp:31:29: warning: left operand of comma operator has no effect [-Wunused-value] for(j = 1, k = N; j <= N, k >= 1; j++, k--) ^ user.cpp:40:29: warning: left operand of comma operator has no effect [-Wunused-value] for(j = 1, k = N; j <= N, k >= 1; j++, k--) ^ user.cpp: In function ‘void read()’: user.cpp:49:15: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k; ^ user.cpp: In function ‘void solve()’: user.cpp:82:33: warning: left operand of comma operator has no effect [-Wunused-value] for(j = 1, k = N; j <= N, k >= 1; j++, k--) ^ user.cpp:119:33: warning: left operand of comma operator has no effect [-Wunused-value] for(i = 1, k = N; i <= N, k >= 1; i++, k--) ^