Create graph1.java

graph1.java

@@ -0,0 +1,57 @@
+//problem1
+class Solution {
+    public int findJudge(int n, int[][] trust) {
+        int[] arr=new int[n];
+        for(int[] t:trust){
+            arr[t[0]-1]--;
+            arr[t[1]-1]++;
+        }
+        for(int i=0;i<n;i++){
+            if(arr[i]==n-1){
+                return i+1;
+            }
+        }
+        return -1;
+    }
+}
+//problem2
+import java.util.*;
+
+class Main {
+    public boolean hasPath(int[][] maze, int[] start, int[] destination) {
+        int m = maze.length;
+        int n = maze[0].length;
+        int[][] dirs = {
+                {1,0},
+                {-1,0},
+                {0,1},
+                {0,-1}
+        };
+        Queue<int[]> q = new LinkedList<>();
+        q.add(new int[]{start[0], start[1]});
+        maze[start[0]][start[1]] = -1;
+        while (!q.isEmpty()) {
+            int[] curr = q.poll();
+            if (curr[0] == destination[0] &&
+                curr[1] == destination[1])
+                return true;
+            for (int[] dir : dirs) {
+                int r = curr[0] + dir[0];
+                int c = curr[1] + dir[1];
+                while (r >= 0 && r < m &&
+                       c >= 0 && c < n &&
+                       maze[r][c] != 1) {
+                    r += dir[0];
+                    c += dir[1];
+                }
+                r -= dir[0];
+                c -= dir[1];
+                if (maze[r][c] != -1) {
+                    maze[r][c] = -1;
+                    q.add(new int[]{r, c});
+                }
+            }
+        }
+        return false;
+    }
+}