add new solutions

solutions/7/q700/solution.go

@@ -0,0 +1,24 @@
+package q700
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func searchBST(root *TreeNode, val int) *TreeNode {
+	if root == nil {
+		return nil
+	}
+
+	switch {
+	case val == root.Val:
+		return root
+	case val > root.Val:
+		return searchBST(root.Right, val)
+	default:
+		return searchBST(root.Left, val)
+	}
+}
+
+var _ = searchBST

solutions/7/q724/solution.go

@@ -0,0 +1,21 @@
+package q724
+
+func pivotIndex(nums []int) int {
+	sumL, sumR := 0, 0
+	for _, n := range nums {
+		sumR += n
+	}
+
+	for i := range nums {
+		sumR -= nums[i]
+		if i > 0 {
+			sumL += nums[i-1]
+		}
+		if sumL == sumR {
+			return i
+		}
+	}
+	return -1
+}
+
+var _ = pivotIndex

solutions/7/q746/solution.go

@@ -0,0 +1,11 @@
+package q746
+
+func minCostClimbingStairs(cost []int) int {
+	minCost := make([]int, len(cost)+1)
+	for i := 2; i < len(minCost); i++ {
+		minCost[i] = min(minCost[i-2]+cost[i-2], minCost[i-1]+cost[i-1])
+	}
+	return minCost[len(minCost)-1]
+}
+
+var _ = minCostClimbingStairs