304. Range Sum Query 2D - Immutable #77

Original file line number	Diff line number	Diff line change
Expand Up		@@ -5,7 +5,7 @@ import "testing"
		func TestAddAndSearchWord(t *testing.T) {
		obj := Constructor()

	for _, word := range []string{"bad", "dad", "mad"}{
	for _, word := range []string{"bad", "dad", "mad"}{
		obj.AddWord(word)
		}

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35 changes: 35 additions & 0 deletions src/304_Range_Sum_Query_2D/rsq.go

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		@@ -0,0 +1,35 @@
	/*
	304. Range Sum Query 2D - Immutable
	https://leetcode.com/problems/range-sum-query-2d-immutable/
	*/
	// 2019年02月27日

	package rsq

	// NumMatrix 累计区域和的数组
	type NumMatrix struct {
	dp [][]int
	}

	// Constructor 初始化构造函数
	func Constructor(matrix [][]int) NumMatrix {
	if len(matrix) == 0 \|\| len(matrix[0]) == 0 {
	return NumMatrix{}
	}
	numMatrix := NumMatrix{dp: make([][]int, len(matrix)+1)}
	for i := 0; i < len(numMatrix.dp); i++ {
	numMatrix.dp[i] = make([]int, len(matrix[0])+1)
	}

	for i := 1; i <= len(matrix); i++ {
	for j := 1; j <= len(matrix[0]); j++ {
	numMatrix.dp[i][j] = numMatrix.dp[i-1][j] + numMatrix.dp[i][j-1] - numMatrix.dp[i-1][j-1] + matrix[i-1][j-1]
	}
	}
	return numMatrix
	}

	// SumRegion 求区域和
	func (nm *NumMatrix) SumRegion(row1 int, col1 int, row2 int, col2 int) int {
	return nm.dp[row2+1][col2+1] - nm.dp[row1][col2+1] - nm.dp[row2+1][col1] + nm.dp[row1][col1]
	}

35 changes: 35 additions & 0 deletions src/304_Range_Sum_Query_2D/rsq_test.go

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		@@ -0,0 +1,35 @@
	package rsq

	import "testing"

	func TestSunRegion(t *testing.T) {
	matrix := [][]int{
	{3, 0, 1, 4, 2},
	{5, 6, 3, 2, 1},
	{1, 2, 0, 1, 5},
	{4, 1, 0, 1, 7},
	{1, 0, 3, 0, 5},
	}

	obj := Constructor(matrix)

	testData := [][]int{
	{2, 1, 4, 3},
	{1, 1, 2, 2},
	{1, 2, 2, 4},
	}
	expected := []int{8, 11, 12}

	for index, data := range testData {
	if res := obj.SumRegion(data[0], data[1], data[2], data[3]); res != expected[index] {
	t.Errorf("expected %d, got %d", expected[index], res)
	}
	}

	if res := Constructor([][]int{}); res.dp != nil {
	t.Errorf("expected nil, got %v", res.dp)
	}
	if res := Constructor(make([][]int, 3)); res.dp != nil {
	t.Errorf("expected nil, got %v", res.dp)
	}
	}

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