init

top-100-liked/7_test.go

@@ -0,0 +1,36 @@
+package top100liked
+
+import (
+	"testing"
+)
+
+// https://leetcode.cn/problems/trapping-rain-water/?envType=study-plan-v2&envId=top-100-liked
+
+func trap(height []int) (ans int) {
+	n := len(height)
+	if n == 0 {
+		return
+	}
+
+	leftMax := make([]int, n)
+	leftMax[0] = height[0]
+	for i := 1; i < n; i++ {
+		leftMax[i] = max(leftMax[i-1], height[i])
+	}
+
+	rightMax := make([]int, n)
+	rightMax[n-1] = height[n-1]
+	for i := n - 2; i >= 0; i-- {
+		rightMax[i] = max(rightMax[i+1], height[i])
+	}
+
+	for i, h := range height {
+		ans += min(leftMax[i], rightMax[i]) - h
+	}
+	return
+}
+
+func TestS7(t *testing.T) {
+	println(trap([]int{0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1}))
+	// {4,2,0,3,2,5}
+}