-
星空
class Solution(object): def fourSumCount(self, A, B, C, D): """ :type A: List[int] :type B: List[int] :type C: List[int] :type D: List[int] :rtype: int """ ans = 0 cnt = collections.defaultdict(int) for a in A: for b in B: cnt[a + b] += 1 for c in C: for d in D: ans += cnt[-(c + d)] return ans
-
星空
public int fourSumCount(int[] A, int[] B, int[] C, int[] D) { Map<Integer, Integer> map = new HashMap<>(); for(int i=0; i<C.length; i++) { for(int j=0; j<D.length; j++) { int sum = C[i] + D[j]; map.put(sum, map.getOrDefault(sum, 0) + 1); } } int res=0; for(int i=0; i<A.length; i++) { for(int j=0; j<B.length; j++) { res += map.getOrDefault(-1 * (A[i]+B[j]), 0); } } return res; }
-
星空
class Solution(object): def fourSumCount(self, A, B, C, D): AB = collections.Counter(a+b for a in A for b in B) return sum(AB[-c-d] for c in C for d in D)
-