Merge pull request #209 from 0xff-dev/master

Add solution and test-cases for problem 1314

Author: Cori1109

leetcode/1301-1400/1314.Matrix-Block-Sum/README.md

@@ -1,26 +1,25 @@
 # [1314.Matrix Block Sum][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 a `m x n` matrix `mat` and an integer `k`, return a matrix `answer` where each `answer[i][j]` is the sum of all elements `mat[r][c]` for:
+
+- `i - k <= r <= i + k,`
+- `j - k <= c <= j + k,` and
+- `(r, c)` is a valid position in the matrix.
+
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: mat = [[1,2,3],[4,5,6],[7,8,9]], k = 1
+Output: [[12,21,16],[27,45,33],[24,39,28]]
 ```
 
-## 题意
-> ...
+__Example 2:__
 
-## 题解
-
-### 思路1
-> ...
-Matrix Block Sum
-```go
+```
+Input: mat = [[1,2,3],[4,5,6],[7,8,9]], k = 2
+Output: [[45,45,45],[45,45,45],[45,45,45]]
 ```
 
 

leetcode/1301-1400/1314.Matrix-Block-Sum/Solution.go

@@ -1,5 +1,55 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(mat [][]int, k int) [][]int {
+	m, n := len(mat), len(mat[0])
+	cols := make([]int, n)
+	rows := make([]int, m)
+	for col := 0; col < n; col++ {
+		rows[0] = mat[0][col]
+		for row := 1; row < m; row++ {
+			mat[row][col] += mat[row-1][col]
+			rows[row] = mat[row][col]
+		}
+
+		mat[0][col] = mat[m-1][col]
+		if k < m {
+			mat[0][col] = mat[k][col]
+		}
+		for row := 1; row < m; row++ {
+			end, start := row+k, row-k-1
+			if end >= m {
+				end = m - 1
+			}
+
+			mat[row][col] = rows[end]
+			if start >= 0 {
+				mat[row][col] -= rows[start]
+			}
+		}
+	}
+
+	for row := 0; row < m; row++ {
+		cols[0] = mat[row][0]
+		for col := 1; col < n; col++ {
+			mat[row][col] += mat[row][col-1]
+			cols[col] = mat[row][col]
+		}
+
+		mat[row][0] = mat[row][n-1]
+		if k < n {
+			mat[row][0] = mat[row][k]
+		}
+		for col := 1; col < n; col++ {
+			left, right := col-k-1, col+k
+			if right >= n {
+				right = n - 1
+			}
+			mat[row][col] = cols[right]
+			if left >= 0 {
+				mat[row][col] -= cols[left]
+			}
+		}
+	}
+
+	return mat
 }

leetcode/1301-1400/1314.Matrix-Block-Sum/Solution_test.go

@@ -10,21 +10,21 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		matrix [][]int
+		k      int
+		expect [][]int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", [][]int{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}, 1, [][]int{{12, 21, 16}, {27, 45, 33}, {24, 39, 28}}},
+		{"TestCase2", [][]int{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}, 2, [][]int{{45, 45, 45}, {45, 45, 45}, {45, 45, 45}}},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.matrix, c.k)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with input-mat: %v, input-k: %v",
+					c.expect, got, c.matrix, c.k)
 			}
 		})
 	}