The Smallest Difference

Given two array of integers(the first array is array A, the second array is arrayB), now we are going to find a element in array A which is A[i], and another element in array B which is B[j], so that the difference between A[i] and B[j] (|A[i] - B[j]|) is as small as possible, return their smallest difference.

Example

For example, given array A = [3,6,7,4], B = [2,8,9,3], return 0。

分析：

首先sort, 然后用两个指针分别指向两个array的头部，谁小移动谁。

 public class Solution {
     /**
      * @param A, B: Two integer arrays.
      * @return: Their smallest difference.
      */
     public int smallestDifference(int[] A, int[] B) {
         Arrays.sort(A);
         Arrays.sort(B);
 
         int pa = ;
         int pb = ;
 
         int diff = Integer.MAX_VALUE;
 
         while (pa < A.length && pb < B.length) {
             if (A[pa] < B[pb]) {
                 diff = Math.min(diff, Math.abs(A[pa] - B[pb]));
                 pa++;
             } else if (A[pa] == B[pb]) {
                 return ;
             } else {
                 diff = Math.min(diff, Math.abs(A[pa] - B[pb]));
                 pb++;
             }
         }
         return diff;
     }
 }