面试题 04.01. 节点间通路

构建有向连通图,然后进行BFS,如果能到达target就返回true 否则返回false

class Solution {
    public boolean findWhetherExistsPath(int n, int[][] graph, int start, int target) {
        Map> map = new HashMap<>();
        for (int i=0;i set = new HashSet<>();
                set.add(go[1]);
                map.put(go[0],set);
            }else {
                HashSet set = map.get(go[0]);
                set.add(go[1]);
            }
        }
        boolean[] visited = new boolean[n];
        linkedList queue = new linkedList<>();
        queue.add(start);
        visited[start] = true;
        while (!queue.isEmpty()){
            int size = queue.size();
            for (int i=0;i set = map.get(first);
                    for (int key : set){
                        if (!visited[key]){
                            queue.add(key);
                            visited[key] = true;
                        }
                    }
                }
            }
        }
        return false;
    }
}