View Compilation Error

0_0_20582434_29683.cpp:7:1: error: expected ',' or ';' before 'int'
 int c[maxn],n;
 ^
0_0_20582434_29683.cpp: In function 'int sum(int)':
0_0_20582434_29683.cpp:17:12: error: 'c' was not declared in this scope
         s+=c[i];
            ^
0_0_20582434_29683.cpp: In function 'void add(int, int)':
0_0_20582434_29683.cpp:24:15: error: 'n' was not declared in this scope
     while( i<=n )
               ^
0_0_20582434_29683.cpp:26:9: error: 'c' was not declared in this scope
         c[i]+=val;
         ^
0_0_20582434_29683.cpp: In function 'int main()':
0_0_20582434_29683.cpp:39:14: error: 'n' was not declared in this scope
         cin>>n;
              ^
0_0_20582434_29683.cpp:40:16: error: 'c' was not declared in this scope
         memset(c,0,sizeof(c));
                ^