Merge pull request #2828 from catherinexrk/master

图论103.md水流问题 提交Go的DFS方案

Author: youngyangyang04

problems/kamacoder/0103.水流问题.md

@@ -413,6 +413,81 @@ if __name__ == "__main__":
 ```
 
 ### Go
+```go
+package main
+
+import (
+    "os"
+    "fmt"
+    "strings"
+    "strconv"
+    "bufio"
+)
+
+var directions = [][]int{{0, -1}, {0, 1}, {-1, 0}, {1, 0}} // 四个方向的偏移量
+
+func main() {
+    scanner := bufio.NewScanner(os.Stdin)
+    
+    scanner.Scan()
+    lineList := strings.Fields(scanner.Text())
+    N, _ := strconv.Atoi(lineList[0])
+    M, _ := strconv.Atoi(lineList[1])
+    
+    grid := make([][]int, N)
+    visited := make([][]bool, N) // 用于标记是否访问过
+    for i := 0; i < N; i++ {
+        grid[i] = make([]int, M)
+        visited[i] = make([]bool, M)
+        scanner.Scan()
+        lineList = strings.Fields(scanner.Text())
+        
+        for j := 0; j < M; j++ {
+            grid[i][j], _ = strconv.Atoi(lineList[j])
+        }
+    }
+    
+    // 遍历每个单元格，使用DFS检查是否可达两组边界
+    for i := 0; i < N; i++ {
+        for j := 0; j < M; j++ {
+            canReachFirst, canReachSecond := dfs(grid, visited, i, j)
+            if canReachFirst && canReachSecond {
+                fmt.Println(strconv.Itoa(i) + " " + strconv.Itoa(j))
+            }
+        }
+    }
+}
+
+func dfs(grid [][]int, visited [][]bool, startx int, starty int) (bool, bool) {
+    visited[startx][starty] = true
+    canReachFirst := startx == 0 || starty == 0 || startx == len(grid)-1 || starty == len(grid[0])-1
+    canReachSecond := startx == len(grid)-1 || starty == len(grid[0])-1 || startx == 0 || starty == 0
+    
+    if canReachFirst && canReachSecond {
+        return true, true
+    }
+    
+    for _, direction := range directions {
+        nextx := startx + direction[0]
+        nexty := starty + direction[1]
+        
+        if nextx < 0 || nextx >= len(grid) || nexty < 0 || nexty >= len(grid[0]) {
+            continue
+        }
+        
+        if grid[nextx][nexty] <= grid[startx][starty] && !visited[nextx][nexty] {
+            hasReachFirst, hasReachSecond := dfs(grid, visited, nextx, nexty)
+            if !canReachFirst {
+                canReachFirst = hasReachFirst
+            }
+            if !canReachSecond {
+                canReachSecond = hasReachSecond
+            }
+        }
+    }
+    return canReachFirst, canReachSecond
+}
+```
 
 ### Rust