题目链接:https://leetcode.cn/problems/check-if-all-the-integers-in-a-range-are-covered/
class Solution {
public:bool isCovered(vector<vector<int>>& ranges, int left, int right) {vector<int> sum(55,0); //sum就是差分数组for(int i = 0;i < ranges.size();i ++){int l = ranges[i][0],r = ranges[i][1];sum[l] ++,sum[r + 1] --;}for(int i = 1;i < 51;i ++) sum[i] += sum[i - 1];for(int i = left;i <= right;i ++){if(sum[i] < 1){return false;}}return 1;}
};