Merge pull request #1291 from 0xff-dev/1504

Add solution and test-cases for problem 1504

Author: 6boris

leetcode/1501-1600/1504.Count-Submatrices-With-All-Ones/1.jpg

@@ -1,28 +1,41 @@
 # [1504.Count Submatrices With All Ones][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+Given an `m x n` binary matrix `mat`, return the number of **submatrices** that have all ones.
+
+**Example 1:**  
 
-**Example 1:**
+![1](./1.jpg)
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: mat = [[1,0,1],[1,1,0],[1,1,0]]
+Output: 13
+Explanation: 
+There are 6 rectangles of side 1x1.
+There are 2 rectangles of side 1x2.
+There are 3 rectangles of side 2x1.
+There is 1 rectangle of side 2x2. 
+There is 1 rectangle of side 3x1.
+Total number of rectangles = 6 + 2 + 3 + 1 + 1 = 13.
 ```
 
-## 题意
-> ...
+**Example 2:**  
 
-## 题解
+![2](./2.jpg)
 
-### 思路1
-> ...
-Count Submatrices With All Ones
-```go
 ```
-
+Input: mat = [[0,1,1,0],[0,1,1,1],[1,1,1,0]]
+Output: 24
+Explanation: 
+There are 8 rectangles of side 1x1.
+There are 5 rectangles of side 1x2.
+There are 2 rectangles of side 1x3. 
+There are 4 rectangles of side 2x1.
+There are 2 rectangles of side 2x2. 
+There are 2 rectangles of side 3x1. 
+There is 1 rectangle of side 3x2. 
+Total number of rectangles = 8 + 5 + 2 + 4 + 2 + 2 + 1 = 24.
+```
 
 ## 结语
 

leetcode/1501-1600/1504.Count-Submatrices-With-All-Ones/2.jpg

@@ -1,5 +1,28 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(mat [][]int) int {
+	n := len(mat[0])
+	heights := make([]int, n)
+	res := 0
+	for _, row := range mat {
+		for i := 0; i < n; i++ {
+			if row[i] == 0 {
+				heights[i] = 0
+			} else {
+				heights[i]++
+			}
+		}
+		stack := [][3]int{{-1, 0, -1}}
+		for i, h := range heights {
+			for len(stack) > 1 && stack[len(stack)-1][2] >= h {
+				stack = stack[:len(stack)-1]
+			}
+			top := stack[len(stack)-1]
+			j, prev := top[0], top[1]
+			cur := prev + (i-j)*h
+			stack = append(stack, [3]int{i, cur, h})
+			res += cur
+		}
+	}
+	return res
 }

leetcode/1501-1600/1504.Count-Submatrices-With-All-Ones/README.md

@@ -10,12 +10,11 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs [][]int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", [][]int{{1, 0, 1}, {1, 1, 0}, {1, 1, 0}}, 13},
+		{"TestCase2", [][]int{{0, 1, 1, 0}, {0, 1, 1, 1}, {1, 1, 1, 0}}, 24},
 	}
 
 	//	开始测试
@@ -30,10 +29,10 @@ func TestSolution(t *testing.T) {
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }