29 lines
590 B
Go
29 lines
590 B
Go
package top100liked
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import "testing"
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// https://leetcode.cn/problems/subarray-sum-equals-k/description/?envType=study-plan-v2&envId=top-100-liked
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// 这题好难，理解不能
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func subarraySum(nums []int, k int) int {
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freq := make(map[int]int)
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freq[0] = 1
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cur := 0
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res := 0
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for _, v := range nums {
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cur += v
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if f, ok := freq[cur-k]; ok {
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res += f
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}
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freq[cur]++
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}
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return res
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}
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func TestS10(t *testing.T) {
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println(subarraySum([]int{1, 1, 1}, 2))
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println(subarraySum([]int{1, 2, 3}, 3))
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println(subarraySum([]int{1}, 0))
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println(subarraySum([]int{-1, -1, 1}, 0))
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}
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