Merge Sorted Array

problem:

Given two sorted integer arrays A and B, merge B into A as one sorted array.

Note:
You may assume that A has enough space to hold additional elements from B. The number of elements initialized in A and B are m and n respectivel

Sol:

class Solution {
public:
    void merge(int A[], int m, int B[], int n) {
        m--;
        n--;
        while (1) {
            if (n < 0)
                return;
            else if (m < 0) {
                while (n >= 0) {
                    A[n] = B[n];
                    n--;
                }
                return;
            }
            else if (A[m] == B[n]) {
                A[m + n + 1] = A[m];
                A[m + n] = A[m];
                m--;
                n--;
            } else if (A[m] > B[n]) {
                A[m + n + 1] = A[m];
                m--;
            } else {
                A[m + n + 1] = B[n];
                n--;
            }
        }
    }
};

====== Smaller one ======

void merge(int A[], int m, int B[], int n) {

        // Start typing your C/C++ solution below

        // DO NOT write int main() function

        int count=m+n-1;

        m--; n--;

        while (m>=0 && n>=0){

            A[count--] = A[m]>B[n]? A[m--]:B[n--];

        }

        while (n>=0){ A[count--] = B[n--];}

    }

OR

void merge(int A[], int m, int B[], int n) {

        // Start typing your C/C++ solution below

        // DO NOT write int main() function

        int k=m+n-1;

        int i=m-1;

        int j=n-1;

        while (i>=0 && j>=0){

            if (A[i]>B[j]){

                A[k--]=A[i--];

            }else{

                A[k--]=B[j--];

            }

        }

        while (j>=0){

            A[k--]=B[j--];

        }

        return;

    }




=== This attempt ====




void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) { if (n == 0) { return; } else if (m == 0) { nums1 = nums2; return; } while (m > 0 && n > 0) { if (nums1[m - 1] == nums2[n - 1]) { nums1[m + n - 1] = nums1[m - 1]; nums1[m + n - 2] = nums1[m - 1]; m--; n--; } else if (nums1[m - 1] > nums2[n - 1]) { nums1[m + n - 1] = nums1[m - 1]; m--; } else { nums1[m + n - 1] = nums2[n - 1]; n--; } } if (m == 0) { while (n > 0) { nums1[n - 1] = nums2[n - 1]; n--; } } return; }




======== Better one ====




class Solution { public: void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) { while (n > 0) { int first = (m > 0 ? nums1[m - 1] : INT_MIN); int second = (n > 0 ? nums2[n - 1]: INT_MIN); if (m == 0 || second >= first) { nums1[m + n - 1] = second; n--; } else { nums1[m + n - 1] = first; m--; } } } };