20251015 baekjoon

code_study/Baekjoon/java/_1865.java

@@ -0,0 +1,77 @@
+import java.util.*;
+
+class Node {
+    int u, v, w;
+
+    Node(int u, int v, int w) {
+        this.u = u;
+        this.v = v;
+        this.w = w;
+    }
+}
+
+class _1865 {
+
+    static boolean bellman_ford(Node[] edges, Node info) {
+        int N = info.u;
+        int M = info.v;
+        int W = info.w;
+        
+        int[] distance = new int[N+1];
+        Arrays.fill(distance, 0);
+
+        for(int n=0; n<N; n++) {
+            for(int i=0; i<2*M+W; i++) {
+                int current = edges[i].u;
+                int next = edges[i].v;
+                int time = edges[i].w;
+
+                if(distance[next] > distance[current] + time) {
+                    if(n==N-1) return true;
+
+                    distance[next] = distance[current] + time;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    public static void main(String[] args) {
+        
+        Scanner sc = new Scanner(System.in);
+        int T = sc.nextInt();
+        
+        for(int t=0; t<T; t++) {
+            int N = sc.nextInt();
+            int M = sc.nextInt();
+            int W = sc.nextInt();
+            Node info = new Node(N, M, W);
+
+            Node[] edges = new Node[2*M+W];
+
+            for(int i=0; i<2*M; i+=2) {
+                int u = sc.nextInt();
+                int v = sc.nextInt();
+                int w = sc.nextInt();
+
+                edges[i] = new Node(u, v, w);
+                edges[i+1] = new Node(v, u, w);
+            }
+
+            for(int i=0; i<W; i++) {
+                int u = sc.nextInt();
+                int v = sc.nextInt();
+                int w = sc.nextInt();
+
+                edges[2*M+i] = new Node(u, v, (-1)*w);
+            }
+
+            boolean negative_cycle = bellman_ford(edges, info);
+
+            System.out.println(negative_cycle ? "YES" : "NO");
+        }
+
+        sc.close();
+    }
+}