1224. 最大相等频率

Author: EndlessCheng

leetcode/weekly/158/d/d.go

@@ -0,0 +1,52 @@
+package main
+
+import "sort"
+
+// github.com/EndlessCheng/codeforces-go
+func maxEqualFreq(a []int) (ans int) {
+	c := map[int]int{}
+	cc := make([]int, len(a)+1)
+	for i, v := range a {
+		c[v]++
+		c := c[v]
+		cc[c]++
+		if cc[c]*c == i {
+			ans = i + 1
+		} else if cc[c]*c == i+1 && i+1 < len(a) {
+			ans = i + 2
+		}
+	}
+	return
+}
+
+func maxEqualFreq2(a []int) (ans int) {
+	c := map[int]int{}
+	cc := map[int]int{}
+	for i, v := range a {
+		if c := c[v]; cc[c] > 1 {
+			cc[c]--
+		} else if cc[c] == 1 {
+			delete(cc, c)
+		}
+		c[v]++
+		cc[c[v]]++
+		if len(cc) > 2 {
+			continue
+		}
+		cs := make([]int, 0, len(cc))
+		for c := range cc {
+			cs = append(cs, c)
+		}
+		sort.Ints(cs)
+		if len(cc) == 1 {
+			if cs[0] == 1 || cc[cs[0]] == 1 {
+				ans = i + 1
+			}
+		} else {
+			if cs[0] == 1 && cc[cs[0]] == 1 || cs[1]-cs[0] == 1 && cc[cs[1]] == 1 {
+				ans = i + 1
+			}
+		}
+	}
+	return
+}