洛谷P2879 区间统计 - 贪心

#include 
#include 
#include 
#include 
#include 
using namespace std;
#define debug(x) cerr << #x << "=" << x << endl;
const int MAXN = 1000000 + 10;
int a[MAXN],l=1,r=0,k,n,mians,d[MAXN],sum[MAXN],t[MAXN],dif[MAXN],h;
mapint, int>, bool> book; 
void update(int x, int p) {
    while(p <= n) {
        t[p] += x;
        p += p&-p;
    }
}
int getsum(int p) {
    int sum = 0;
    while(p) {
        sum += t[p];
        p -= p&-p;
    }
    return sum;
}
int main() {
    cin >> n >> l >> h >> r;
    for(int i=1; i<=r; i++) {
        int a,b;
        cin >> a >> b;
        if(a > b) swap(a, b);
    //左边这样不对 difa+1万一先减后加就成0了 有多次操作呢 if(dif[a+1] && dif[b]) continue;
        if(book[make_pair(a,b)]) continue;
        book[make_pair(a,b)] = 1;
        dif[a+1]--;
        dif[b]++;
    }
    for(int i=1; i<=n; i++) {
        sum[i] = sum[i-1] + dif[i];
        int nowh = h + sum[i];
        cout << nowh << endl;
    }
    return 0;
}