扫描线

int main(){    map<int ,int >mp1,mp2;    int n;    cin>>n;    for(int i=1;i<=n;i++)    {        int x,y;        cin>>x>>y;        mp1[x]++;        mp2[y]++;    }    cout<<mp1[1]<<" ";    for(int i=2;i<=n;i++)    {        mp1[i]+=mp1[i-1]-mp2[i-1];        cout<<mp1[i]<<" ";    }    cout<<endl;    return 0;}