20201203

20201203/main.go

@@ -0,0 +1,30 @@
+package main
+
+func main() {
+
+}
+
+func goodPairsCount(src []int) int {
+	count := 0
+	l := len(src)
+	for i := 0; i < l; i++ {
+		for j := i + 1; j < l; j++ {
+			if src[i] == src[j] {
+				count++
+			}
+		}
+	}
+	return count
+}
+
+func goodPairsCount2(src []int) int {
+	m := make(map[int]int)
+	for _, n := range src {
+		m[n] += 1
+	}
+	count := 0
+	for _, v := range m {
+		count += v * (v - 1) / 2
+	}
+	return count
+}