[Algorithm] 6. Merge Two Sorted Arrays

Description

Merge two given sorted integer array A and B into a new sorted integer array.

Example

A=[1,2,3,4]

B=[2,4,5,6]

return [1,2,2,3,4,4,5,6]

Challenge

How can you optimize your algorithm if one array is very large and the other is very small?

Solution

     /**
      * @param A: sorted integer array A
      * @param B: sorted integer array B
      * @return: A new sorted integer array
      */
     vector<int> mergeSortedArray(vector<int> &A, vector<int> &B) {
         // write your code here
         vector<int> res;
         int maxSize= A.size() > B.size() ? A.size() : B.size();
         int index_a=,index_b=;

         for(int i=; i<A.size()+B.size(); i++)
         {
             if(index_b==B.size()){
                 for(int i=index_a; i<A.size(); i++)     res.push_back(A[i]);
                 return res;
             }

             if(index_a==A.size()){
                 for(int i=index_b; i<B.size(); i++)     res.push_back(B[i]);
                 return res;
             }

             if (A[index_a] <= B[index_b]){
                 res.push_back(A[index_a]);
                 index_a++;
             }else{
                 res.push_back(B[index_b]);
                 index_b++;
             }
         }
         return res;
     }

Tips

Select the minimum element from two arrays in every loop.