add new solutions

solutions/37/q3719/solution.go

@@ -0,0 +1,53 @@
+package q3719
+
+var seen [6000]bool
+
+func longestBalanced(nums []int) int {
+	// Map numbers to reduce the range
+	mapped := make(map[int]int, len(nums))
+	nextEven, nextOdd := 0, 1
+	for i := range nums {
+		if m, ok := mapped[nums[i]]; ok {
+			nums[i] = m
+		} else if nums[i]%2 == 0 {
+			mapped[nums[i]] = nextEven
+			nums[i] = nextEven
+			nextEven += 2
+		} else {
+			mapped[nums[i]] = nextOdd
+			nums[i] = nextOdd
+			nextOdd += 2
+		}
+	}
+	numRange := max(nextEven, nextOdd)
+	copy(seen[:3000], seen[3000:]) // init
+
+	longest := 0
+	for i := 1; i < len(nums); i++ {
+		copy(seen[:numRange], seen[numRange:]) // reset
+		odd, even := 0, 0
+		for j := i; j >= 0; j-- {
+			num := nums[j]
+			if seen[num] {
+				if even == odd {
+					longest = max(longest, i-j+1)
+				}
+				continue
+			}
+			seen[num] = true
+
+			if num%2 == 0 {
+				even++
+			} else {
+				odd++
+			}
+			if even == odd {
+				longest = max(longest, i-j+1)
+			}
+		}
+	}
+
+	return longest
+}
+
+var _ = longestBalanced