251116

25/11/go/2654.go

@@ -0,0 +1,38 @@
+package B
+
+func minOperations(nums []int) int {
+	n, gcdAll, cnt1 := len(nums), 0, 0
+	for _, x := range nums {
+		gcdAll = gcd(gcdAll, x)
+		if x == 1 {
+			cnt1++
+		}
+	}
+	if gcdAll > 1 {
+		return -1
+	}
+	if cnt1 > 0 {
+		return n - cnt1
+	}
+
+	minSize := n
+	for i := range nums {
+		g := 0
+		for j, x := range nums[i:] {
+			g = gcd(g, x)
+			if g == 1 {
+				// 这里本来是 j+1，把 +1 提出来合并到 return 中
+				minSize = min(minSize, j)
+				break
+			}
+		}
+	}
+	return minSize + n - 1
+}
+
+func gcd(a, b int) int {
+	for a != 0 {
+		a, b = b%a, a
+	}
+	return b
+}