luoguT21777

Posted 2020-10-24 poorpool

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
typedef long long ll;
int n, m;
ll a[500005], uu, vv, lst, qzh[500005];
struct SGT{
    ll sum[2000005], tag[2000005], fla[2000005], zdz[2000005];
    void update(int o, int l, int r, ll k){
        sum[o] += (qzh[r]-qzh[l-1]) * k;
        tag[o] += k;
        zdz[o] += a[r] * k;
    }
    void reset(int o, int l, int r, ll k){
        sum[o] = (r-l+1) * k;
        zdz[o] = fla[o] = k;
        tag[o] = 0;
    }
    void pushDown(int o, int l, int r, int lson, int rson, int mid){
        if(fla[o]!=-1){
            reset(lson, l, mid, fla[o]);
            reset(rson, mid+1, r, fla[o]);
            fla[o] = -1;
        }
        if(tag[o]){
            update(lson, l, mid, tag[o]);
            update(rson, mid+1, r, tag[o]);
            tag[o] = 0;
        }
    }
    int queryPos(int o, int l, int r, ll k){
        if(l==r)    return l;
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            pushDown(o, l, r, lson, rson, mid);
            if(zdz[lson]>=k)    return queryPos(lson, l, mid, k);
            else    return queryPos(rson, mid+1, r, k);
        }
    }
    ll querySum(int o, int l, int r, int x, int y){
        if(l>=x && r<=y)    return sum[o];
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            ll ans=0;
            pushDown(o, l, r, lson, rson, mid);
            if(x<=mid)  ans += querySum(lson, l, mid, x, y);
            if(mid<y)   ans += querySum(rson, mid+1, r, x, y);
            return ans;
        }
    }
    void modify(int o, int l, int r, int x, int y, ll k){
        if(l>=x && r<=y)    reset(o, l, r, k);
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            pushDown(o, l, r, lson, rson, mid);
            if(x<=mid)  modify(lson, l, mid, x, y, k);
            if(mid<y)   modify(rson, mid+1, r, x, y, k);
            sum[o] = sum[lson] + sum[rson];
            zdz[o] = zdz[rson];
        }
    }
}sgt;
int main(){
    cin>>n>>m;
    for(int i=1; i<=n; i++) scanf("%lld", &a[i]);
    sort(a+1, a+1+n);
    for(int i=1; i<=n; i++) qzh[i] = qzh[i-1] + a[i];
    memset(sgt.fla, -1, sizeof(sgt.fla));
    while(m--){
        scanf("%lld %lld", &uu, &vv);
        sgt.update(1, 1, n, uu-lst);
        lst = uu;
        if(sgt.zdz[1]<vv){
            printf("0\n");
            continue;
        }
        int pos=sgt.queryPos(1, 1, n, vv);
        printf("%lld\n", sgt.querySum(1, 1, n, pos, n)-(n-pos+1)*vv);
        sgt.modify(1, 1, n, pos, n, vv);
    }
    return 0; 
}