Compilare: user.cpp: In function ‘void pre_mat()’: user.cpp:36:52: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses] m1=maxim(r[i][j][k-1], r[i][j-(1<<k-1)][k-1]); ^ user.cpp:37:35: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses] m2=maxim(r[i-(1<<k-1)][j][k-1], r[i-(1<<k-1)][j-(1<<k-1)][k-1]); ^ user.cpp:37:58: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses] m2=maxim(r[i-(1<<k-1)][j][k-1], r[i-(1<<k-1)][j-(1<<k-1)][k-1]); ^ user.cpp:37:70: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses] m2=maxim(r[i-(1<<k-1)][j][k-1], r[i-(1<<k-1)][j-(1<<k-1)][k-1]); ^