Merge branch 'master' of github.com:youngyangyang04/leetcode-master

problems/kamacoder/0044.开发商购买土地.md

@@ -212,13 +212,14 @@ public class Main {
         int horizontalCut = 0;
         for (int i = 0; i < n; i++) {
             horizontalCut += horizontal[i];
-            result = Math.min(result, Math.abs(sum - 2 * horizontalCut));
+            result = Math.min(result, Math.abs((sum - horizontalCut) - horizontalCut));
+            // 更新result。其中，horizontalCut表示前i行的和，sum - horizontalCut表示剩下的和，作差、取绝对值，得到题目需要的“A和B各自的子区域内的土地总价值之差”。下同。
         }
 
         int verticalCut = 0;
         for (int j = 0; j < m; j++) {
             verticalCut += vertical[j];
-            result = Math.min(result, Math.abs(sum - 2 * verticalCut));
+            result = Math.min(result, Math.abs((sum - verticalCut) - verticalCut));
         }
 
         System.out.println(result);
@@ -526,3 +527,89 @@ int main()
 }
 
 ```
+
+### Go
+
+前缀和
+
+```go
+package main
+
+import (
+    "fmt"
+    "os"
+    "bufio"
+    "strings"
+    "strconv"
+    "math"
+)
+    
+func main() {
+    var n, m int
+    
+    reader := bufio.NewReader(os.Stdin)
+    
+    line, _ := reader.ReadString('\n')
+    line = strings.TrimSpace(line)
+    params := strings.Split(line, " ")
+    
+    n, _ = strconv.Atoi(params[0])
+    m, _ = strconv.Atoi(params[1])//n和m读取完成
+    
+    land := make([][]int, n)//土地矩阵初始化
+    
+    for i := 0; i < n; i++ {
+        line, _ := reader.ReadString('\n')
+        line = strings.TrimSpace(line)
+        values := strings.Split(line, " ")
+        land[i] = make([]int, m)
+        for j := 0; j < m; j++ {
+            value, _ := strconv.Atoi(values[j])
+            land[i][j] = value
+        }
+    }//所有读取完成
+    
+    //初始化前缀和矩阵
+    preMatrix := make([][]int, n+1)
+	for i := 0; i <= n; i++ {
+		preMatrix[i] = make([]int, m+1)
+	}
+    
+    for a := 1; a < n+1; a++ {
+        for b := 1; b < m+1; b++ {
+            preMatrix[a][b] = land[a-1][b-1] + preMatrix[a-1][b] + preMatrix[a][b-1] - preMatrix[a-1][b-1]
+        }
+    }
+    
+    totalSum := preMatrix[n][m]
+    
+    minDiff := math.MaxInt32//初始化极大数，用于比较
+    
+    //按行分割
+    for i := 1; i < n; i++ {
+        topSum := preMatrix[i][m]
+        
+        bottomSum := totalSum - topSum
+        
+        diff := int(math.Abs(float64(topSum - bottomSum)))
+        if diff < minDiff {
+            minDiff = diff
+        }
+    }
+    
+    //按列分割
+    for j := 1; j < m; j++ {
+        topSum := preMatrix[n][j]
+        
+        bottomSum := totalSum - topSum
+        
+        diff := int(math.Abs(float64(topSum - bottomSum)))
+        if diff < minDiff {
+            minDiff = diff
+        }
+    }    
+    
+    fmt.Println(minDiff) 
+}
+```
+