20251022 baekjoon

code_study/Baekjoon/swift/1167.swift

@@ -0,0 +1,47 @@
+func findMaxLenNode(start n: Int, of graph: [[(node: Int, dist: Int)]]) -> (node: Int, dist: Int) {
+    var result = (node: n, dist: 0)
+    var visited = Array(repeating: false, count: graph.count+1)
+    var stack: [(node: Int, dist: Int)] = []
+    stack.append(result)
+    visited[n] = true
+    
+    while !stack.isEmpty {
+        if let (cur_node, cur_dist) = stack.popLast(){
+            
+            if cur_dist > result.dist {
+                result = (node: cur_node, dist: cur_dist)
+            }
+            
+            for next in graph[cur_node] {
+                if !visited[next.node] {
+                    stack.append((node: next.node, dist: cur_dist + next.dist))
+                    visited[next.node] = true
+                }
+            }
+        }
+    }
+    
+    return result
+}
+
+
+if let V = Int(readLine() ?? "") {
+    var tree: [[(node: Int, dist: Int)]] = Array(repeating: [], count: V+1)
+    
+    for _ in 1...V {
+        if let line = readLine(),
+           let info = line.split(separator: " ").compactMap({Int($0)}) as? [Int]
+        {
+            let u = info[0]
+            var i = 1
+            
+            while info[i] != -1 {
+                tree[u].append((node: info[i], dist: info[i+1]))
+                i += 2
+            }
+        }
+    }
+    
+    let start = findMaxLenNode(start: 1, of: tree).node
+    print(findMaxLenNode(start: start, of: tree).dist)
+}