Main.cc: In function ‘int main()’: Main.cc:16:17: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(a[i-1][j]='.') a[i-1][j]='@'; ~~~~~~~~~^~~~ Main.cc:17:17: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(a[i+1][j]='.') a[i+1][j]='@'; ~~~~~~~~~^~~~ Main.cc:18:17: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(a[i][j-1]='.') a[i][j-1])='@'; ~~~~~~~~~^~~~ Main.cc:18:32: error: expected ‘;’ before ‘)’ token if(a[i][j-1]='.') a[i][j-1])='@'; ^ Main.cc:18:31: warning: statement has no effect [-Wunused-value] if(a[i][j-1]='.') a[i][j-1])='@'; ~~~~~~~~^ Main.cc:19:17: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(a[i][j+1]='.') a[i][j+1])='@'; ~~~~~~~~~^~~~ Main.cc:19:32: error: expected ‘;’ before ‘)’ token if(a[i][j+1]='.') a[i][j+1])='@'; ^ Main.cc:19:31: warning: statement has no effect [-Wunused-value] if(a[i][j+1]='.') a[i][j+1])='@'; ~~~~~~~~^ Main.cc:25:14: warning: suggest parentheses around assignment used as truth value [-Wparentheses] if(a[i][j]='@') cnt++; ~~~~~~~^~~~