feat: add go solution to lc problem: No.0202 (doocs#828)

Author: Yeqi Tao

solution/0200-0299/0202.Happy Number/Solution.go

@@ -0,0 +1,35 @@
+var resultMap map[int]bool
+
+func init() {
+	resultMap = make(map[int]bool)
+}
+
+func calculate(num int) int {
+	sum := 0
+	for num > 0 {
+		k := num % 10
+		sum += k * k
+		num = num / 10
+	}
+	return sum
+}
+
+func isHappy(n int) bool {
+	tmpMap := make(map[int]bool)
+	for ; ; n = calculate(n) {
+		f, ok := resultMap[n]
+		if f || n == 1 {
+			for k := range tmpMap {
+				resultMap[k] = true
+			}
+			return true
+		}
+		if (!f && ok) || tmpMap[n] {
+			for k := range tmpMap {
+				resultMap[k] = false
+			}
+			return false
+		}
+		tmpMap[n] = true
+	}
+}