【lintcode】6. Merge Two Sorted Arrays

Description

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

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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?

class Solution {
public:
    /**
     * @param A and B: sorted integer array A and B.
     * @return: A new sorted integer array
     */
    vector mergeSortedArray(vector &A, vector &B) {
        int lenA = A.size();
        int lenB = B.size();
        
        vector C(lenA + lenB);
        
        int i = 0;
        int j = 0;
        int k = 0;
        
        for (i = 0, j = 0, k = 0; i < lenA && j < lenB;) {
            if (A[i] < B[j]) {
                C[k++] = A[i++];
            }
            else {
                C[k++] = B[j++];
            }
        }
        
        while (i < lenA) {
            C[k++] = A[i++];
        }
        
        while (j < lenB) {
            C[k++] = B[j++];
        }
        
        return C;
    }
};

思路：

1、最经典简单的双指针解法。