数组剔除元素后的乘积

 1 public class Solution {
 2     /**
 3      * @param A: Given an integers array A
 4      * @return: A Long array B and B[i]= A[0] * ... * A[i-1] * A[i+1] * ... * A[n-1]
 5      */
 6     public ArrayList<Long> productExcludeItself(ArrayList<Integer> A) {
 7         // write your code
 8         ArrayList<Long> B = new ArrayList<Long>();
 9         long leftb = 1;
10         long rightb = 1;
11         for(int i=0;i<A.size();i++){
12             if(i==0){
13                 leftb =1;
14             }else{
15                 leftb = leftb*A.get(i-1);
16             }
17             for(int j=i+1;j<A.size();j++){
18                 rightb = rightb*A.get(j);
19             }
20             long bi =leftb*rightb;
21             B.add(bi);
22             rightb=1;
23         }
24         return B;
25     }
26 }