Files
2020-08-07 17:06:53 +08:00

19 lines
281 B
Go

package leetcode
func fourSumCount(A []int, B []int, C []int, D []int) int {
m := make(map[int]int, len(A)*len(B))
for _, a := range A {
for _, b := range B {
m[a+b]++
}
}
ret := 0
for _, c := range C {
for _, d := range D {
ret += m[0-c-d]
}
}
return ret
}