View Compilation Error

0_0_22067373_30350.cpp: In function 'int main()':
0_0_22067373_30350.cpp:30:20: error: 'len' was not declared in this scope
                 dp[len]=a[i];
                    ^
0_0_22067373_30350.cpp:42:20: error: 'len' was not declared in this scope
                 dp[len]=b[i];
                    ^