LeetCode 第14双周赛

T1:十六进制魔术数字

解题思路:就直接按照题意来，先将字符串转换为16进制，然后在根据题目进行判断(这里偷了个懒,直接利用了java库函数????)

import java.math.BigInteger;
class Solution {
    public String toHexspeak(String num) {
        BigInteger bigInteger = new BigInteger(num,10);
        String s = bigInteger.toString(16);
        StringBuilder sb = new StringBuilder();
        for (char a:s.toCharArray()) {
            if (a=='0') a='O';
            if (a=='1') a= 'I';
            if (a>='2' && a<='9')return "ERROR";
            sb.append(a);
        }
        return sb.toString().toUpperCase();
    }
}

T2:删除区间

解题思路:题意就是要求将与toBeRemoved区间范围内的部分都删除，用例已经提示的十分清楚了。其实就是一个分类讨论的题目。

    public List> removeInterval(int[][] intervals, int[] toBeRemoved) {
        int n = intervals.length;
        List<List<Integer>> res = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            if (intervals[i][1]<=toBeRemoved[0] || intervals[i][0]>=toBeRemoved[1]){
                ArrayList<Integer> tmp = new ArrayList<>();
                tmp.add(intervals[i][0]);
                tmp.add(intervals[i][1]);
                res.add(tmp);
            }else if (intervals[i][1]>toBeRemoved[0] && intervals[i][0]<=toBeRemoved[0] && toBeRemoved[1]>intervals[i][1]){
                ArrayList<Integer> tmp = new ArrayList<>();
                tmp.add(intervals[i][0]);
                tmp.add(toBeRemoved[0]);
                res.add(tmp);
            }else if (intervals[i][0]<toBeRemoved[1] && intervals[i][0]>=toBeRemoved[0] && toBeRemoved[1]<intervals[i][1]){
                ArrayList<Integer> tmp = new ArrayList<>();
                tmp.add(toBeRemoved[1]);
                tmp.add(intervals[i][1]);
                res.add(tmp);
            }else if (intervals[i][0]<=toBeRemoved[0] && intervals[i][1]>=toBeRemoved[1]){
                ArrayList<Integer> tmp1 = new ArrayList<>();
                tmp1.add(intervals[i][0]);
                tmp1.add(toBeRemoved[0]);
                res.add(tmp1);
                ArrayList<Integer> tmp2 = new ArrayList<>();
                tmp2.add(toBeRemoved[1]);
                tmp2.add(intervals[i][1]);
                res.add(tmp2);
            }
        }
        return res; 
    }

T3：