View Compilation Error

0_0_29197934_26849.cpp:6:9: error: 'n' was not declared in this scope
 int cal(n)
         ^
0_0_29197934_26849.cpp:7:1: error: expected ',' or ';' before '{' token
 {
 ^
0_0_29197934_26849.cpp: In function 'int main()':
0_0_29197934_26849.cpp:22:29: error: 'cal' cannot be used as a function
         printf("%d\n" ,cal(n));
                             ^