304 solved. (#77)

Author: zwfang

src/0211_add_and_search_word/add_and_search_word_test.go

@@ -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)
 	}
 

src/304_Range_Sum_Query_2D/rsq.go

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

src/304_Range_Sum_Query_2D/rsq_test.go

@@ -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)
+	}
+}