View Compilation Error

0_0_26066733_6729.cpp: In function 'int main()':
0_0_26066733_6729.cpp:70:31: error: no match for 'operator[]' (operand types are 'std::map<int, int> [100050]' and 'std::vector<int>')
                     num += mpx[ys[j - 1]][index];
                               ^