32 lines
776 B
Go
32 lines
776 B
Go
package top100liked
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import "testing"
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// https://leetcode.cn/problems/first-missing-positive/description/?envType=study-plan-v2&envId=top-100-liked
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func firstMissingPositive(nums []int) int {
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n := len(nums)
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for i := range nums {
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for nums[i] >= 1 && nums[i] <= n && nums[i] != i+1 {
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if nums[i] != nums[nums[i]-1] { // 关键条件，否则会死循环 [1, 1]
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nums[i], nums[nums[i]-1] = nums[nums[i]-1], nums[i]
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} else {
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break
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}
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}
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}
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for i, v := range nums {
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if v != i+1 {
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return i + 1
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}
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}
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return n + 1
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}
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func TestS17(t *testing.T) {
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// println(firstMissingPositive([]int{1, 2, 0}))
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// println(firstMissingPositive([]int{3, 4, -1, 1}))
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// println(firstMissingPositive([]int{7, 8, 9, 11, 12}))
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println(firstMissingPositive([]int{1, 1}))
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}
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