义乌中学暑假集训 2021.07.16 D

#include<bits/stdc++.h>
#define I inline
#define W while
#define RI register int 
#define Cn const
#define CI Cn int& 
#define gc getchar
#define pc putchar
#define LL long long
using namespace std;
I void read(int& x){RI f=1;char c=gc();x=0;W(!('0'<=c&&c<='9')) f=c^'-'?f:-1,c=gc();W('0'<=c&&c<='9') x=x*10+(c-'0'),c=gc();x*=f;}
I void write(LL x){x<0&&(pc('-'),x=-x),x>=10&&(write(x/10),0),pc(x%10+'0');}
Cn int N=1e6+10;
int n,m,inf=2e9,cnt;
#define P pair<LL,int>
#define MP make_pair
#define fi first
#define se second
P b[N<<1];
LL sc,Ans;
priority_queue<LL> Q1;
priority_queue<P> Q2;
int main(){
    RI i,j,x,y;LL t;for(read(n),read(m),i=1;i<=n;i++) read(x),b[++cnt]=MP(x,-1);
    for(i=1;i<=m;i++) read(x),read(y),b[++cnt]=MP(x,y),sc+=y;
    if(sc<n) return puts("-1"),0;
    for(sort(b+1,b+cnt+1),i=1;i<=cnt;i++) if(~b[i].se){
        W(!Q1.empty()&&b[i].se&&b[i].fi<Q1.top()) t=b[i].fi-Q1.top(),Q1.pop(),b[i].se--,Q2.push(MP(b[i].fi+t,0)),Ans+=t;
        b[i].se&&(b[i].se--,Q2.push(MP(b[i].fi,i)),0);
    }else{
        t=2e12;if(!Q2.empty()) t=b[i].fi-Q2.top().fi,j=Q2.top().se,Q2.pop(),b[j].se&&(b[j].se--,Q2.push(MP(b[j].fi,j)),0);
        Ans+=t,Q1.push(b[i].fi+t);
    }return write(Ans),0;
}