题解 | #合并两个有序数组#

class Solution {
public:
    void merge(int A[], int m, int B[], int n) {
      if (m == 0) {
        std::copy(B, B + n, A);
        return ;
      } else if (n ==0) {
        return ;
      }
      
      std::copy(A, A + m, A + n);
      int a = n, b = 0, fin = 0;
      
      while (b < n && a < m + n) {
        if (A[a] < B[b]) {
          A[fin] = A[a];
          ++a;
        } else {
          A[fin] = B[b];
          ++b;
        }
        ++fin;
      }
      
      while (b < n) {
        A[fin] = B[b];
        ++b;
        ++fin;
      }
      
      while (a < m + n) {
        A[fin] = A[a];
        ++a;
        ++fin;
      }
    }
};