C. Covered Points Count(思维+差分)

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

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思路:值域较大，差分扫一遍不允许。需要离散化后差分。对线段端点进行差分。遍历map就可以获得当前到lastpos(边扫边维护)区间内的点的覆盖次数。长度相减即可。

#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=2e5+1000;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
map<LL,LL>map1;
vector<LL>ans[maxn];
int main(void)
{
  cin.tie(0);std::ios::sync_with_stdio(false);
  LL n;cin>>n;
  for(LL i=1;i<=n;i++){
     LL l,r;cin>>l>>r;
     map1[l]++;map1[r+1]--;
  }
  LL res=0;
  LL lastpos=0;
  for(auto i:map1){
     LL cnt=i.first-lastpos;
     ans[res].push_back(cnt);
     res+=i.second;
     lastpos=i.first;
  }
  for(LL i=1;i<=n;i++){
     LL f=0;
     for(auto j:ans[i]){
        f+=j;
     }
     cout<<f<<" ";
  }
return 0;
}