[JOI 2014 Final]IOI 馒头

#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
using namespace std;
inline int read(){
    int f=1,ans=0;char c=getchar();
    while(c<‘0‘||c>‘9‘){if(c==‘-‘)f=-1;c=getchar();}
    while(c>=‘0‘&&c<=‘9‘){ans=ans*10+c-‘0‘;c=getchar();}
    return f*ans;
}
const int MAXN=10001;
int val[MAXN<<2],w[MAXN<<2],c[MAXN<<2],s[MAXN<<2],dp[MAXN<<2],n,m;
bool cmp(int x1,int x2){return x1>x2;}
int main(){
    memset(dp,127/3,sizeof(dp));
    n=read(),m=read();
    for(int i=1;i<=n;i++) val[i]=read();sort(val+1,val+n+1,cmp);
    for(int i=1;i<=n;i++) s[i]=s[i-1]+val[i];
    for(int i=1;i<=m;i++) w[i]=min(read(),n),c[i]=read();dp[0]=0;
    for(int i=1;i<=m;i++){
        for(int j=2*n;j>=w[i];j--) dp[j]=min(dp[j],dp[j-w[i]]+c[i]);
    }
    for(int i=2*n-1;i>=0;i--) dp[i]=min(dp[i],dp[i+1]);
    int maxn=0;
    for(int i=1;i<=n;i++) maxn=max(maxn,s[i]-dp[i]);
    cout<<maxn;
}