LeetCode974.和可被K整除的子数组
题目来源：
https://leetcode-cn.com/problems/subarray-sums-divisible-by-k/
题目描述：
class Solution {
public int subarraysDivByK(int[] A, int K) {
int[] map = new int[K];
map[0]=1;
int count =0;
int remainder=0;
for(int i=0;i<A.length;i++) {
remainder=(remainder+A[i])%K;
if(remainder<0) {
remainder+=K;
}
count+=map[remainder];
map[remainder]++;
}
return count;
}
}