[LintCode] 两个排序数组的中位数

 class Solution {
 public:
     /**
      * @param A: An integer array.
      * @param B: An integer array.
      * @return: a double whose format is *.5 or *.0
      */
     double findMedianSortedArrays(vector<int> A, vector<int> B) {
         // write your code here
         int m = A.size(), n = B.size();
         if (m > n) return findMedianSortedArrays(B, A);
         int imin = , imax = m, half = (m + n + ) / , i, j, num1, num2;
         while (imin <= imax) {
             i = (imin + imax) / ;
             j = half - i;
             if (j >  && i < m && B[j - ] > A[i])
                 imin = i + ;
             else if (i >  && j < n && A[i - ] > B[j])
                 imax = i - ;
             else {
                 if (!i) num1 = B[j - ];
                 else if (!j) num1 = A[i - ];
                 else num1 = max(A[i - ], B[j - ]);
                 break;
             }
         }
         if ((m + n) % ) return num1;
         if (i == m) num2 = B[j];
         else if (j == n) num2 = A[i];
         else num2 = min(A[i], B[j]);
         return (num1 + num2) / 2.0;
     }
 };