View Compilation Error

0_0_17176686_13209.cpp: In function 'int main()':
0_0_17176686_13209.cpp:25:20: error: 'i' was not declared in this scope
         int len = (i
                    ^
0_0_17176686_13209.cpp:25:20: error: expected ')' at end of input
0_0_17176686_13209.cpp:25:20: error: expected ',' or ';' at end of input
0_0_17176686_13209.cpp:25:20: error: expected '}' at end of input
0_0_17176686_13209.cpp:25:20: error: expected '}' at end of input