CodeForces 1000C Covered Points Count (Interval segment coverage issues, differential)

https://codeforces.com/problemset/problem/1000/C

 

 

 

 

 

 

 

 

 

Meaning of the questions:

Has n segments, covering [L _I , R & lt _I ], the final output sequence is the number of cover layers 1 to n of points.

Ideas:

Interval segment coverage problem, the first reaction Fenwick tree, tree line, looked at the size of the data, they can not so much space.

Only with a difference

 

 code show as below:

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <iostream>
 4 #include <string>
 5 #include <math.h>
 6 #include <algorithm>
 7 #include <vector>
 8 #include <stack>
 9 #include <queue>
10 #include <set>
11 #include <map>
12 #include <math.h>
13 const int INF=0x3f3f3f3f;
14 typedef long long LL;
15 const int mod=1e9+7;
16 #define Bug cout<<"---------------------"<<endl
17 const int maxn=2*1e5+10;
18 using namespace std;
19 
20 pair<LL,int> p[2*maxn];//注意要开两倍空间 
21 LL ans[maxn];
22 
23 int main()
24 {
25     int n;
26     scanf("%d",&n);
27     int cnt = 0;
28     for(int i = 0;i < n;i++)
29     {
30         LL l,r;//注意是long long 
31         scanf("%lld %lld",&l,&r);
32         p[i*2] = make_pair(l,1);
33         p[i*2+1] = make_pair(r+1,-1);
34     }
35     sort(p,p+n*2);
36     LL now = 0;//当前点的覆盖层数 
37     for(int i = 0;i < n*2;i++)
38     {
39         now += p[i].second;
40         if(p[i].first == p[i+1].first)    continue;//叠加差分 
41         ans[now] += p[i+1].first - p[i].first; 
42     }
43     for(int i=1;i<=n;i++)
44         printf("%lld ",ans[i]);
45     return 0;
46 }