View Compilation Error

0_0_39241237_9521.cpp: In function 'void add(int, int)':
0_0_39241237_9521.cpp:12:17: error: 'n' was not declared in this scope
   12 |     while (i <= n)
      |                 ^
0_0_39241237_9521.cpp:14:9: error: 'c' was not declared in this scope
   14 |         c[i] += val;
      |         ^
0_0_39241237_9521.cpp: In function 'int sum(int)':
0_0_39241237_9521.cpp:23:14: error: 'c' was not declared in this scope
   23 |         s += c[i];
      |              ^