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top-100-liked/12_test.go

@@ -0,0 +1,59 @@
+package top100liked
+
+import "testing"
+
+// https://leetcode.cn/problems/minimum-window-substring/?envType=study-plan-v2&envId=top-100-liked
+
+func minWindow(s string, t string) string {
+	if len(t) > len(s) {
+		return ""
+	}
+	need := make(map[byte]int)
+	for _, v := range []byte(t) {
+		need[v]++
+	}
+
+	window := make(map[byte]int)
+	valid := 0
+	left := 0
+	minLen := len(s) + 1
+	start := 0
+
+	for right := 0; right < len(s); right++ {
+		ch := s[right]
+		if _, ok := need[ch]; ok {
+			window[ch]++
+			if window[ch] == need[ch] {
+				valid++
+			}
+		}
+
+		for valid == len(need) {
+			if right-left+1 < minLen {
+				minLen = right - left + 1
+				start = left
+			}
+
+			d := s[left]
+			left++
+			if _, ok := need[d]; ok {
+				if window[d] == need[d] {
+					valid--
+				}
+				window[d]--
+			}
+		}
+	}
+
+	if minLen == len(s)+1 {
+		return ""
+	}
+
+	return s[start : start+minLen]
+}
+
+func TestS12(t *testing.T) {
+	println(minWindow("ADOBECODEBANC", "ABC"))
+	println(minWindow("a", "a"))
+	println(minWindow("a", "aa"))
+}