.\407.接雨水-ii.go err----------

侯利朋 · 侯利朋 · commit 347ec31a84ee · 2019-09-06T20:02:25.000+08:00
diff --git a/407.接雨水-ii.go b/407.接雨水-ii.go
@@ -0,0 +1,144 @@
+/*
+ * @lc app=leetcode.cn id=407 lang=golang
+ *
+ * [407] 接雨水 II
+ *
+ * https://leetcode-cn.com/problems/trapping-rain-water-ii/description/
+ *
+ * algorithms
+ * Hard (31.26%)
+ * Likes:    93
+ * Dislikes: 0
+ * Total Accepted:    909
+ * Total Submissions: 2.9K
+ * Testcase Example:  '[[1,4,3,1,3,2],[3,2,1,3,2,4],[2,3,3,2,3,1]]'
+ *
+ * 给定一个 m x n 的矩阵，其中的值均为正整数，代表二维高度图每个单元的高度，请计算图中形状最多能接多少体积的雨水。
+ * 
+ * 
+ * 
+ * 说明:
+ * 
+ * m 和 n 都是小于110的整数。每一个单位的高度都大于 0 且小于 20000。
+ * 
+ * 
+ * 
+ * 示例：
+ * 
+ * 给出如下 3x6 的高度图:
+ * [
+ * ⁠ [1,4,3,1,3,2],
+ * ⁠ [3,2,1,3,2,4],
+ * ⁠ [2,3,3,2,3,1]
+ * ]
+ * 
+ * 返回 4。
+ * 
+ * 
+ * 
+ * 
+ * 如上图所示，这是下雨前的高度图[[1,4,3,1,3,2],[3,2,1,3,2,4],[2,3,3,2,3,1]] 的状态。
+ * 
+ * 
+ * 
+ * 
+ * 
+ * 下雨后，雨水将会被存储在这些方块中。总的接雨水量是4。
+ * 
+ */
+ //  × testcase: '[[12,13,1,12],[13,4,13,12],[13,8,10,12],[12,13,12,12],[13,13,13,13]]'
+// err-------------------------------
+ func trapRainWater(heightMap [][]int) int {
+    rows := len(heightMap)
+    if rows == 0 {
+        return 0
+    }
+    cols := len(heightMap[0])
+    if cols == 0 {
+        return 0
+    }
+    
+    left := make([][]int, rows)
+    for i:=0; i<rows; i++{
+        left[i] = make([]int, cols)
+    }
+    for i:=0; i<rows; i++ {
+        left[i][0] = heightMap[i][0]
+        for j:=1; j<cols; j++{
+            if heightMap[i][j] > left[i][j-1]{
+                 left[i][j] = heightMap[i][j]
+            } else {
+                left[i][j] = left[i][j-1]
+            }
+        }
+    }
+    
+    right := make([][]int, rows)
+    for i:=0; i<rows; i++{
+        right[i] = make([]int, cols)
+    }
+    for i:=0; i<rows; i++ {
+        right[i][cols-1] = heightMap[i][cols-1]
+        for j:=cols-2; j>=0; j--{
+            if heightMap[i][j] > right[i][j+1]{
+                 right[i][j] = heightMap[i][j]
+            } else {
+                right[i][j] = right[i][j+1]
+            }
+        }
+    }
+    
+    up := make([][]int, rows)
+    for i:=0; i<rows; i++{
+        up[i] = make([]int, cols)
+    }
+    for c:=0; c<cols;c++ {
+        up[0][c] = heightMap[0][c]
+        for r:=1; r<rows;r++{
+            if heightMap[r][c] > up[r-1][c] {
+                up[r][c] = heightMap[r][c]
+            }else{
+                up[r][c] = up[r-1][c]
+            }
+        }
+    }
+    
+    down := make([][]int, rows)
+    for i:=0; i<rows; i++{
+        down[i] = make([]int, cols)
+    }
+    for c:=0; c<cols;c++ {
+        down[rows-1][c] = heightMap[rows-1][c]
+        for r:=rows-2; r>=0;r--{
+            if heightMap[r][c] > down[r+1][c] {
+                down[r][c] = heightMap[r][c]
+            }else{
+                down[r][c] = down[r+1][c]
+            }
+        }
+    }
+    sum := 0 
+    for r:=1; r<rows-1;r++{
+        for c:=1;c<cols-1;c++{
+            if heightMap[r][c] < left[r][c-1] && 
+            heightMap[r][c] < right[r][c+1] &&
+            heightMap[r][c] < up[r-1][c] &&
+            heightMap[r][c] < down[r+1][c]{
+                sum += min4(left[r][c-1],right[r][c+1], up[r-1][c],down[r+1][c]) - heightMap[r][c]
+            }
+        }
+    }
+    return sum
+}
+
+func min4(a,b,c,d int) int{
+    if a<=b&& a<= c && a<= d{
+        return a
+    }else if b<=a&& b<= c && b<= d{
+        return b
+    }else if c<=a&& c<= b && c<= d{
+        return c
+    }
+    return d
+}
+
