[Solved] Some problem about the algorithm of merging two lists

by


The line

vector<int> list3(list1.size()+list2.size());

creates a vector of type int and inserts list1.size()+list2.size() default contructed elements. You want to create an empty vector of type int and reserve memory for list1.size()+list2.size() elements. Use 

vector<int> list3;
list3.reserve(list1.size()+list2.size());

solved Some problem about the algorithm of merging two lists