很妙的差分思想~~

题目链接: https://www.acwing.com/problem/content/description/103/

#include<iostream>
#include<algorithm>

using namespace std;

const int N = 10010;

int n,p,h,m;
int q[N];
bool flag[N][N];

int main()
{
    cin>>n>>p>>h>>m;
    q[1] = h;
    while(m--)
    {
        int a,b;
        cin>>a>>b;
        if(a > b) swap(a,b);
        if(!flag[a][b])
        {
            flag[a][b] = 1;
            q[a+1] -= 1,q[b] += 1;
        }
    }
    for(int i = 1;i <= n;i++)
    {
        q[i] += q[i-1];
        cout<<q[i]<<endl;
    }
    return 0;
}