[简单] 997. 找到小镇的法官

https://leetcode-cn.com/problems/find-the-town-judge/

 

  我只会写一些垃圾代码：

class Solution {
    public int findJudge(int n, int[][] trust) {
        class NodeMap {
            int resident; // 小镇居民
            int truster;  // 小镇居民信任的人.

            public int getResident() {
                return resident;
            }

            public void setResident(int resident) {
                this.resident = resident;
            }

            public int getTruster() {
                return truster;
            }

            public void setTruster(int truster) {
                this.truster = truster;
            }

            @Override
            public boolean equals(Object o) {
                if (this == o) return true;
                if (o == null || getClass() != o.getClass()) return false;
                NodeMap nodeMap = (NodeMap) o;
                return resident == nodeMap.resident && truster == nodeMap.truster;
            }

            @Override
            public int hashCode() {
                return Objects.hash(resident, truster);
            }

            public NodeMap(int resident, int truster) {
                this.resident = resident;
                this.truster = truster;
            }
        }

        int ret = -1;
        if((trust == null || trust.length == 0)) {
            if(n == 1)
                return 1;
            else
                return -1;
        }

        if (trust.length == 1) {
            ret = trust[0][1];
        }
        else {
            // 获取信任映射关系
            List<NodeMap> allTrustMap = new ArrayList<>();
            Set<Integer> setResident = new HashSet<>(); // 居民列表
            for (int m = 0; m < trust.length; m++) {
                allTrustMap.add(new NodeMap(trust[m][0], trust[m][1]));
                setResident.add(trust[m][0]);
                setResident.add(trust[m][1]);
            }
            int iResidentCount = setResident.size();


            List<Integer> st = new ArrayList<>();// 获取不相信任何人的列表.
            for (int i = 1; i <= n; i++) {
                boolean bNoTruster = false;
                for (NodeMap node : allTrustMap) {
                    if(node.getResident() == i) {
                        bNoTruster = true;
                    }
                }

                if(!bNoTruster) {
                    st.add(i);
                }
            }


            // 检查不信任任何人的列表是否均被所有人新人, 若是则判断为法官.
            for (int m = 0; m < st.size(); m++) {
                int u = st.get(m);// 当前可能是法官的人.

                Set<Integer> setTruster = new HashSet<>();
                for(int k = 1; k <= n; k++) { // 遍历小镇居民
                    if(k == u) continue; // 屏蔽掉当前怀疑是发官的对象.

                    for(NodeMap e : allTrustMap) {
                        int curResident = e.getResident();
                        int curTruster  = e.getTruster();

                        if(k == curResident && u == curTruster) {
                            setTruster.add(k);
                            continue;
                        }
                    }
                }

                if (setTruster.size() >= (iResidentCount - 1)) {
                    ret = u;
                    break;
                }
            }

        }
        return ret;
    }
}