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top-100-liked/10_1_test.go

@@ -0,0 +1,26 @@
+package top100liked
+
+import "testing"
+
+// https://leetcode.cn/problems/continuous-subarray-sum/
+
+func checkSubarraySum(nums []int, k int) bool {
+	idx := make(map[int]int)
+	cur := 0
+	idx[0] = -1
+	for i, v := range nums {
+		cur += v
+		if j, ok := idx[cur%k]; ok {
+			if i-j >= 2 {
+				return true
+			}
+		} else {
+			idx[cur%k] = i
+		}
+	}
+	return false
+}
+
+func TestS10_1(t *testing.T) {
+	println(checkSubarraySum([]int{23, 2, 6, 4, 7}, 13))
+}

top-100-liked/10_test.go

@@ -0,0 +1,28 @@
+package top100liked
+
+import "testing"
+
+// https://leetcode.cn/problems/subarray-sum-equals-k/description/?envType=study-plan-v2&envId=top-100-liked
+// 这题好难，理解不能
+
+func subarraySum(nums []int, k int) int {
+	freq := make(map[int]int)
+	freq[0] = 1
+	cur := 0
+	res := 0
+	for _, v := range nums {
+		cur += v
+		if f, ok := freq[cur-k]; ok {
+			res += f
+		}
+		freq[cur]++
+	}
+	return res
+}
+
+func TestS10(t *testing.T) {
+	println(subarraySum([]int{1, 1, 1}, 2))
+	println(subarraySum([]int{1, 2, 3}, 3))
+	println(subarraySum([]int{1}, 0))
+	println(subarraySum([]int{-1, -1, 1}, 0))
+}

top-100-liked/11_test.go

@@ -0,0 +1,42 @@
+package top100liked
+
+import (
+	"fmt"
+	"testing"
+)
+
+// https://leetcode.cn/problems/sliding-window-maximum/?envType=study-plan-v2&envId=top-100-liked
+
+func maxSlidingWindow(nums []int, k int) []int {
+	if len(nums) == 0 || k == 0 {
+		return []int{}
+	}
+
+	deque := make([]int, 0) // 存下标，单调递减（对应值）
+	result := make([]int, 0, len(nums)-k+1)
+
+	for i := 0; i < len(nums); i++ {
+		// 1. 从队尾移除所有 <= nums[i] 的下标
+		for len(deque) > 0 && nums[deque[len(deque)-1]] <= nums[i] {
+			deque = deque[:len(deque)-1]
+		}
+		// 2. 加入当前下标
+		deque = append(deque, i)
+		// 3. 如果队首下标已出窗口，移除
+		if deque[0] < i-k+1 {
+			deque = deque[1:]
+		}
+		// 4. 窗口形成后，记录最大值
+		if i >= k-1 {
+			result = append(result, nums[deque[0]])
+		}
+	}
+	return result
+}
+
+func TestS11(t *testing.T) {
+	fmt.Printf("%+v", maxSlidingWindow([]int{1, 3, -1, -3, 5, 3, 6, 7}, 3))
+	fmt.Printf("%+v", maxSlidingWindow([]int{1}, 1))
+	fmt.Printf("%+v", maxSlidingWindow([]int{9, 9, 8, 8, 7, 7, 6, 6}, 2))
+	fmt.Printf("%+v", maxSlidingWindow([]int{10, 9, 8, 7, 6, 5}, 3))
+}

top-100-liked/8_test.go

@@ -0,0 +1,57 @@
+package top100liked
+
+import "testing"
+
+// https://leetcode.cn/problems/longest-substring-without-repeating-characters/?envType=study-plan-v2&envId=top-100-liked
+
+// func lengthOfLongestSubstring(s string) int {
+// 	if len(s) == 0 {
+// 		return 0
+// 	}
+// 	if len(s) == 1 {
+// 		return 1
+// 	}
+// 	maxLen := 0
+// 	l, r := 0, 1
+// 	maps := make(map[byte]bool)
+// 	maps[s[l]] = true
+// 	for r < len(s) {
+// 		if !maps[s[r]] {
+// 			// 字符不存在于子串
+// 			maps[s[r]] = true
+// 		} else {
+// 			// 字符存在于字串
+// 			// 从子串依次剔除左侧字符直到与 s[r] 相同的字符
+// 			for l < r && s[l] != s[r] {
+// 				maps[s[l]] = false
+// 				l++
+// 			}
+// 			l++
+// 		}
+// 		r++
+// 		maxLen = max(maxLen, r-l)
+// 	}
+
+// 	return maxLen
+// }
+
+func lengthOfLongestSubstring(s string) int {
+	charIdx := make(map[byte]int)
+	maxLen, left := 0, 0
+	slen := len(s)
+	for right := range slen {
+		ch := s[right]
+		if idx, ok := charIdx[ch]; ok && idx >= left {
+			left = idx + 1 // 直接跳到重复字符的下一个
+		}
+		charIdx[ch] = right
+		maxLen = max(maxLen, right-left+1)
+	}
+	return maxLen
+}
+
+func TestS8(t *testing.T) {
+	println(lengthOfLongestSubstring("abcabcbb"))
+	println(lengthOfLongestSubstring("bbbbb"))
+	println(lengthOfLongestSubstring("pwwkew"))
+}

top-100-liked/9_test.go

@@ -0,0 +1,51 @@
+package top100liked
+
+import (
+	"fmt"
+	"testing"
+)
+
+// https://leetcode.cn/problems/find-all-anagrams-in-a-string/description/?envType=study-plan-v2&envId=top-100-liked
+
+func findAnagrams(s string, p string) []int {
+	result := []int{}
+	if len(s) < len(p) {
+		return result
+	}
+
+	// p 的字符计数
+	pCount := [26]int{}
+	for i := 0; i < len(p); i++ {
+		pCount[p[i]-'a']++
+	}
+
+	// 窗口计数
+	wCount := [26]int{}
+	// 先初始化第一个窗口 [0, len(p)-1]
+	for i := 0; i < len(p); i++ {
+		wCount[s[i]-'a']++
+	}
+
+	// 比较第一个窗口
+	if wCount == pCount {
+		result = append(result, 0)
+	}
+
+	// 滑动窗口
+	for i := len(p); i < len(s); i++ {
+		// 加入新字符
+		wCount[s[i]-'a']++
+		// 移除左边界字符
+		wCount[s[i-len(p)]-'a']--
+		// 比较
+		if wCount == pCount {
+			result = append(result, i-len(p)+1)
+		}
+	}
+
+	return result
+}
+
+func TestS9(t *testing.T) {
+	fmt.Printf("%+v", findAnagrams("cbaebabacd", "abc"))
+}